Preeclampsia in HIV Positive Pregnant Women on Highly Active Anti-Retroviral Therapy:

A matched cohort study

by

Talar Boyajian

A thesis submitted in conformity with the requirements

for the degree of Master of Science

Department of Health Policy, Management and Evaluation

University of Toronto

© Copyright by Talar Boyajian (2010)

ii

Preeclampsia in HIV Positive Pregnant Women on Highly Active Anti-Retroviral Therapy: a matched cohort study

Talar Boyajian

Master of Science Health Policy, Management and Evaluation University of Toronto 2010

Abstract

Background: Some studies have suggested that the risk of preeclampsia in HIV positive

pregnant women has increased since the use of HAART became routine. There is also a

concern that HIV positive women on HAART have a higher risk of adverse fetal outcomes

compared to HIV negative women.

Methods: In this matched retrospective cohort study, the risk of preeclampsia and adverse

fetal outcomes was examined in 91 HIV positive pregnant women receiving HAART and

273 HIV negative pregnant women. Multivariate logistic regression models were used to

adjust for confounding factors.

Results: The risk of preeclampsia and preterm birth did not differ significantly between HIV

positive and HIV negative women. HIV treated with HAART was an independent predictor

for giving birth to a low birthweight baby.

Conclusions: HIV positive women on HAART do not have a higher risk of preeclampsia.

They do however have a higher risk for lower birthweight infants.

iii

Acknowledgments

I would like to extend a sincere thank you to Dr. Kellie Murphy, who has not only been an

outstanding supervisor, but an incredible role model. The difference she makes in the lives of

her patients is truly inspiring, and I can only hope to follow in her footsteps. I am very

thankful to Dr. Prakesh Shah for being a fantastic committee member. His invaluable advice

and help throughout the research process is deeply appreciated.

A sincere thank you to Dr. Whitney Berta for her continuous guidance, and for having faith

in my ability to achieve my goals. This thesis would not have been possible without the

generous help of the staff at Mt. Sinai Health Records, who located and retrieved hundreds of

medical charts for my research.

Thank you to my boyfriend, Armen, for inspiring me, both personally and intellectually. My

gratitude and love goes out to him for the countless hours of editing and counseling he

provided this year, but more importantly for the happiness he brings to my life.

A final, special thanks to my family: To my brothers Garen and Sarmen, for their interest in

my research, for our conversations about preeclampsia, and for listening to any concerns or

frustrations I had throughout the year. To my parents, for all their love and support. Thank

you for giving me this opportunity, for allowing me to prioritize my schoolwork, and for

doing everything in your power to help me accomplish my dreams. This thesis is dedicated to

you.

iv

Table of Contents

INTRODUCTION 1

1.1 HISTORY OF MATERNAL HIV AND HAART 1

1.2 STATEMENT OF THE PROBLEM 4

1.3 RESEARCH OBJECTIVES 6

1.4 RESEARCH HYPOTHESIS 6

1.5 IMPORTANCE & IMPLICATIONS OF THIS RESEARCH 6

BACKGROUND 9

2.1. HIV 9

2.2 HAART AND SAFETY CONCERNS IN PREGNANCY 10

2.2.1 FETAL RISKS 11

2.2.2 MATERNAL RISKS 14

2.3 CURRENT CANADIAN GUIDELINES ON TREATING HIV POSITIVE PREGNANT WOMEN 15

2.4 ETIOLOGY AND PATHOGENESIS OF PREECLAMPSIA 16

2.4.1 THE ROLE OF THE IMMUNE SYSTEM IN PREECLAMPSIA 17

2.4.2 PREECLAMPSIA IN HIV POSITIVE WOMEN 19

2.5 KNOWN RISK FACTORS FOR PREECLAMPSIA 20

LITERATURE REVIEW 23

TABLE 3.1 STUDIES EXAMINING THE RISK OF PREECLAMPSIA IN HIV POSITIVE PREGNANT WOMEN 27

METHODS 29

4.1 POPULATION OF INTEREST AND SAMPLING METHODS 31

4.1.1 SELECTION BIAS 33

4.1.2 SAMPLE SIZE 34

4.2 DATA COLLECTION 34

4.3 OUTCOMES 36

4.3.1 PRIMARY OUTCOME: PREECLAMPSIA 36

4.3.2 SECONDARY OUTCOMES: PRETERM BIRTH, LOW BIRTHWEIGHT, SMALL FOR GESTATIONAL AGE 38

4.4 DATA ANALYSIS 38

v

RESULTS 40

TABLE 5.1 MATERNAL DEMOGRAPHICS 40

TABLE 5.2 PRESENCE OF RISK FACTORS 41

TABLE 5.3 HAART INITIATION AND VIRAL LOAD OF HIV POSITIVE COHORT 42

TABLE 5.4 HIV MEDICATIONS 43

TABLE 5.5 MATERNAL OUTCOMES 44

TABLE 5.6 FETAL OUTCOMES 46

TABLE 5.7 HIV POSITIVE WOMEN WHO DEVELOPED PREECLAMPSIA 47

TABLE 5.8 ADJUSTED COMPARISON OF OUTCOMES 49

DISCUSSION 51

6.1 PRIMARY OUTCOME 51

6.2 SECONDARY OUTCOMES 56

6.3 STUDY LIMITATIONS 58

CONCLUSION 60

APPENDIX 62

DATA COLLECTION TOOL 62

REFERENCES 64

vi

List of Common Acronyms

ALT = Alinine transaminase

AST = Aspartate transaminase

AZT/ZDV = Zidovudine

HIV = Human Immunodeficiency Virus

HAART = Highly Active Anti-Retroviral Therapy

PTD = Pre-term delivery

LBW = Low birthweight

NRTI = Nucleoside Reverse Transcriptase Inhibitor

NNRTI =Non-nucleoside Reverse Transcriptase Inhibitor

NVP = Nevirapine

PI = Protease Inhibitor

SGA = Small for gestational age

1

Introduction

1.1 History of maternal HIV and HAART

Worldwide, there are over 15 million women diagnosed with HIV (1), and at the end of

2008, an estimated 14, 300 were living in Canada (2). Women represent one of the fastest

growing group of people diagnosed with HIV and the majority of them are of childbearing

age (3,4).

The significant public health ramifications associated with HIV infection in women were

recognized in the mid-1980s following the first descriptions of paediatric AIDS (5). Soon

after these initial cases, it became apparent that HIV could be transmitted perinatally from an

HIV positive mother to her child through in utero, intrapartum or postpartum (via breast

milk) exposure. Before preventative interventions were developed, the rate of perinatal

transmission in most developed countries was approximately 25%; however rates as high as

2

48% were observed in other parts of the world, where formula feed is not available or

affordable (6).

By the mid-1990s, a decade into the AIDS pandemic, HIV was expanding at an unrelenting

rate: 33,000 Canadians, including 300 children had been diagnosed with the disease (7). A

pivotal breakthrough in the fight against the perinatal transmission of AIDS finally arrived in

1994, when the Pediatric AIDS Clinical Trail Group released the results from ‘Protocol 076’.

This double-blind randomized placebo-controlled trial tested an intensive regimen of

zidovudine (AZT) consisting of antenatal AZT 5 times a day, intrapartum AZT administered

intravenously, and postpartum prophylaxis for the newborn. The results were remarkable-

25.5% of infants from the placebo group, compared to only 8.3% from the zidovudine group

were confirmed HIV positive. This translated to a two third reduction in the risk of perinatal

transmission following AZT (8). Zidovudine was quickly incorporated in routine prenatal

care for maternal HIV in resource-rich countries like Canada, and efforts were focused on

screening for, and diagnosing HIV early in pregnancy.

Soon after the efficacy of AZT was established for the long-term treatment of HIV, as well

as in preventing perinatal transmission, clinical trials involving Highly Active Anti-

3

Retroviral Therapy (HAART), began in 1995. HAART consists of a combination of three

different antiretroviral drugs and is aimed at preventing the development of resistance to any

given class of antiretroviral.

Subsequent to its release in 1996, HAART had a significant impact on HIV-related mortality

rates. It also proved to be more effective at reducing mother-to-child transmission, than dual

therapy regimens or AZT alone (9). In 1998, the Canadian Medical Association published

clinical guidelines encouraging the use of HAART in managing all HIV-complicated

pregnancies (10), and it quickly became the standard of care across the country.

Current statistics estimate that approximately 90% of known HIV positive pregnant women

in Canada are treated with HAART (4). As a result, the rate of infection in perinatally

exposed infants has decreased from 26.8% in 1995 to 1.9% in 2008 (4). In 2008, only four

out of 209 perinatally exposed infants became infected with the virus (4); however, three of

the four infants did not receive any antiretroviral prophylaxis. Although we cannot claim that

pediatric HIV has been eradicated in Canada, with continued use of HAART, we are

certainly within reach of this goal.

4

1.2 Statement of the problem

Notwithstanding the obvious benefits of HAART, concerns have been raised about its safety

in pregnancy. Recent cohort studies have reported an increase in the incidence of a

pregnancy disorder called preeclampsia in HIV positive pregnant women since the use of

HAART became routine (11-13).

Preeclampsia is a hypertensive disease that occurs in late gestation, affecting 3-8% of all

pregnancies (14,15). If left untreated, it can cause seizures and/or multi-organ system

dysfunction in the mother including central nervous system hemorrhage, stroke, renal failure,

hemolysis, elevated liver enzymes, low platelets and placental abruption. Important long-

term complications of preeclampsia include a two-fold increase in the risk of cardiovascular

disease and mortality later in life (16). Fetal complications include intrauterine growth

restriction, prematurity, and intrauterine or neonatal death.

Preeclampsia and other hypertensive disorders of pregnancy remain leading causes of

maternal and neonatal morbidity and mortality around the world (17). In Canada, it was the

5

leading cause of direct maternal death1 from 1997-2000, accounting for 1 in 5 direct deaths in

pregnancy (18).

Since the advent of HAART in 1996, some investigators have suggested that there may be an

increased risk of preeclampsia in HIV positive women. A survey of 36 hospitals from 11

European countries identified preeclampsia as the most common pregnancy complication in

pregnant women receiving HAART (12). In addition, a large perinatal centre in Spain

detected a 9-fold increase in the number of preeclampsia cases in HIV positive women as the

use of HAART became routine (13). In contrast, other studies have shown either a lower

(19), or no significant difference in risk of preeclampsia (11,20-22) compared to HIV

negative women. Thus, the relationship between HAART and preeclampsia remains unclear,

and more research is needed to clarify the association between the two. A more detailed

literature review follows on page 23.

1 Direct maternal deaths are the result of obstetric complications of pregnancy or labour. This differs

from indirect or incidental maternal deaths, where mortality is due to a pre-existing disease or an

incidental event (e.g. car accident) where the pregnancy is unlikely to have contributed to the

death(18).

6

1.3 Research objectives

The primary objective of this study is to determine whether HIV infection treated with

HAART is associated with an increased risk of preeclampsia.

Secondary outcomes of interest include birth outcomes; in particular, the risk of preterm, low

birth weight, and small for gestational age births following treatment of maternal HIV with

HAART.

1.4 Research hypothesis

Our research hypothesis is that there is a higher risk of preeclampsia in HIV positive women

receiving HAART compared to HIV negative women.

1.5 Importance & implications of this research

Over the past decade, the face of AIDS has shifted away from what used to be a disease that

largely affected homosexual men, to a disease affecting a heterogeneous population

including childbearing women. In 2006, women accounted for approximately 24% of the

HIV diagnoses in Canada (7) -- a proportion substantially greater than it was 10 years ago,

7

when only 7 % of HIV diagnoses were attributed to women (7). Research on the risks

associated with the use of HAART in pregnancy has become increasingly important as more

and more HIV positive women are choosing to become pregnant. In a recent survey, 69% of

HIV positive women of reproductive age in Ontario desired to give birth, and 57% intended

to give birth in the future(23). These proportions have risen over time in North America, and

the use of HAART during pregnancy has become critical in controlling the spread of HIV in

Canada and around the world.

In the 21st century, HIV has become a chronic disease in the developed world, and the

mother-to-child transmission has diminished to less than a percent. However, until the gap in

knowledge on the risks associated with HAART use in pregnancy is addressed, the clinical

use of HAART during pregnancy cannot be maximized without some degree of uncertainty

and risk.

The concern that HIV infection treated with HAART may increase the risk of preeclampsia

is an important one to address, as preeclampsia has been a leading cause of maternal death in

Canada for over 30 years (18,24). If a relationship between HAART and preeclampsia were

established, increased monitoring throughout pregnancy for early signs and symptoms of

8

preeclampsia would be indicated. A greater number of prenatal visits may be advised for

HIV positive patients, as well as increased fetal surveillance in the form of laboratory

assessments, non-stress tests, and/or biophysical profiles. Identifying the use of HAART as a

risk factor for the development of preeclampsia may also help identify candidates for

prophylactic interventions. Preventative therapies such as low dose aspirin and calcium have

shown some benefits in preventing preeclampsia, and may be valuable for HIV positive

patients.

Overall, determining the risk of preeclampsia in HIV positive women on HAART may help

clinicians either prevent preeclampsia through prophylactic interventions or decrease its

severity through early detection, thus reducing the morbidity and mortality related to this

condition.

9

Background

2.1. HIV

Human immunodeficiency virus (HIV) is a retrovirus transmitted as a single stranded

ribonucleic acid (RNA) in a viral phospholipid envelope. When the virus infects the target

cell, the RNA genome is converted to a double-stranded deoxyribonucleic acid (DNA) by a

virally encoded reverse transcriptase present in the virus capsule. This viral DNA has the

ability to integrate into the target cell’s DNA with the help of a virally encoded enzymes, and

host cellular co-factors.

HIV preferentially targets CD4+ T helper lymphocytes, vital cells in the human immune

system. Other immunological cells such as macrophages and dendritic cells are also

vulnerable to infection. HIV infection leads to progressive the loss of CD4+ T lymphocytes

through three main mechanisms: 1) direct killing of infected cells 2) increased rates of

apoptosis in infected cells 3) killing of infected CD4+ T lymphocytes by CD 8 cytotoxic

lymphocytes.

10

Eventually, CD4+ T cell numbers decline below a critical level, and cell-mediated immunity

is completely lost, rendering the individual vulnerable to a host of opportunistic infections

and neoplasia such as pneumocystis jirovecii pneumonia, Kaposi’s sarcoma or central

nervous system (CNS) toxoplasmosis. At this stage of the disease, the patient is diagnosed

with AIDS (Acquired Immune Deficiency Syndrome).

The rate at which HIV progresses to AIDS varies depending on viral, host and environmental

factors. Prior to the advent of HAART, most people infected with HIV progress to AIDS

within 9 to 11 years from the time of infection (25). HAART is the most effective way to

prolong disease progression to AIDS. Once AIDS has been diagnosed, death typically ensues

within a year in untreated patients. The average survival time with HAART is estimated to be

more than 5 years after AIDS diagnosis (26).

2.2 HAART and safety concerns in pregnancy

HAART is a potent therapy that inhibits viral replication and suppresses the level of HIV

RNA in the plasma. It consists of a combination of at least three antiretroviral drugs, which

are divided into four major classes: Nucleoside and nucleotide analogue reverse transcriptase

11

inhibitors (NRTIs), protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors

(NNRTIs), and fusion inhibitors.

2.2.1 Fetal Risks

There is some evidence that the use of HAART in pregnancy may increase the risk of

adverse fetal outcomes such as preterm delivery (PTD) and low birthweight (LBW) or small

for gestational age (SGA) births. However, this risk remains contested due to conflicting

evidence.

An increase in PTD associated with HAART was first reported in a retrospective Swiss

cohort in 1998 (27), and was later confirmed by the European Collaborative study and the

Swiss Mother + Child HIV Cohort Study (28,29). Studies conducted in the UK (30,31),

Germany/Austria (32), Brazil (33), and the United States (34), have also found an increased

risk of PTD in HIV positive women treated with HAART compared to untreated HIV

positive women, or women on ziduvodine monotherapy. Some of the studies demonstrated a

greater risk with the use of a PI-containing HAART, or with early initiation of HAART (i.e.

prior to pregnancy or in first trimester).

12

In contrast to these findings, several studies from North and South America have reported

data that do not suggest an increased risk of PTD associated with HAART, when compared

to no treatment or ziduvodine monotherapy (35-38). In addition, a recent meta-analysis of 14

European and American studies, found that HAART use during pregnancy does not increase

risk of PTD when compared to no therapy in HIV positive women (39).

The risk of LBW and SGA associated with exposure to HAART also remains contested.

While some studies have found no significant risk of LBW and SGA associated with

HAART (34,35,37), other studies have reported increased risk of these outcomes (33,40,41).

Since comparison with untreated HIV positive women or women on ziduvodine

monotherapy is no longer feasible in developed countries, more recent studies have

compared the risk of adverse fetal outcomes in HIV positive women on HAART with the

general, uninfected population (20,22). These studies found that HIV positive women treated

with HAART had a higher risk of PTD compared to the general population. With regards to

LBW, Haeri and colleagues demonstrated an increased risk of LBW (22), while Boer and

colleagues reported an equivalent risk of LBW between HIV positive women on HAART

13

and HIV negative women (20). Taking evidence from all published literature, the risk of

PTD, LBW and SGA associated with HAART remains uncertain.

In terms of congenital defects, animal studies and case reports have linked efavirenz-

containing HAART regimens to central nervous system malformations, such as neural tube

defects (42-44). The relative risk, and causal relationship between efavirenz and neural tube

defects, is unclear. Nevertheless it is classified as an FDA Pregnancy Category D drug2, and

should be avoided in the first trimester.

There is some concern that NRTI drugs may induce mitochondrial toxicity in infants, based

on data from animal studies (45-47) and some human cases (48-50). However, large

observational studies, and prospective cohort studies suggest that the risk, if any, is small and

short-term consequences are minimal (51-53).

Finally, exposure to antiretrovirals in pregnancy has been linked to hematological changes in

infants. Ziduvodine may cause anemia in infants, but it is usually transient and rarely severe

2 For a drug to be classified in Category D, there must be positive evidence of human fetal

risk

14

(54,55). There are also some concerns around a slight reduction in platelets, lymphocytes and

neutrophils in children up to 8 years of age who were exposed to antiretrovirals (56).

2.2.2 Maternal Risks

Mitochondrial dysfunction, and cases of severe lactic acidosis have been reported in HIV-

infected pregnant women receiving prolonged HAART containing didanosine and stavudine

(57,58), and this regimen is no longer prescribed for pregnant women.

Nevirapine (NVP)-containing HAART regimens have been associated with increases in liver

enzymes in non-pregnant individuals leading to hepatic rash and/or toxicity. In some

reported cases, hepatic toxicity has lead to death in pregnant women on NVP-containing

HAART. While it is thought that HAART-related hepatotoxicity may have a female

preponderance, it is unknown whether pregnancy increases this risk (59,60).

PIs have been associated with metabolic abnormalities, including hyperglycemia and

gestational diabetes (36,61-63). Lastly, case reports and observational studies have reported

an increased risk of preeclampsia in women using HAART during pregnancy (12,13),

although this has not been confirmed by other investigators (11,19,20,22).

15

2.3 Current Canadian guidelines on treating HIV positive pregnant women

The use of HAART is the standard of care for the management of HIV-complicated

pregnancies in Canada. Some pregnant women are therapy- naive at presentation, either

because they were newly diagnosed or because their virulogical and immunological status

does not indicate the need for treatment. If this is the case, HAART is initiated at 14 weeks

gestation and should be maintained until delivery (64). Pregnant women who present on

HAART should be switched to a more favourable combination of drugs if the drugs they are

taking are contra-indicated in pregnancy (e.g. efavirenz).

The Canadian consensus guidelines recommend a caesarean delivery for any HIV positive

woman with an unknown or detectable (> 50cpm) viral load, or for women who are co-

infected with hepatitis C. For women on HAART who have an undetectable viral load,

vaginal birth is considered as safe as caesarean delivery (64).

In addition to antenatal HAART, intrapartum prophylaxis is routine with continuous

intravenous administration of ZDV until delivery. Neonatal prophylaxis includes oral

administration of ZDV to the infant, with a dose every 6 hours for the first 6 weeks of life

(64).

16

2.4 Etiology and pathogenesis of preeclampsia

The etiology of preeclampsia remains somewhat of an enigma. Genetic, immunologic,

vascular, hormonal, environmental, nutritional, and behavioral factors have all been proposed

to be involved in the pathophysiology of the disease.

The current pathophysiological mechanism is thought to involve poor invasion of

cytotrophoblast cells of the developing placenta into the spiral arteries of the mother’s uterus,

resulting in poor placentation and poor placental blood flow. Poor placental perfusion

triggers the excessive release of inflammatory factors by the placenta into the maternal

bloodstream. The circulating inflammatory factors target and damage the mother’s vascular

endothelial cells, resulting in systemic hypertension and endothelial dysfunction, which has

the potential to harm many organs in her body (65).

While poor placental implantation has typically been considered the causative factor of

preeclampsia, the development of endothelial dysfunction and systemic hypertension

depends on the extent to which inflammatory factors are released, as well as the maternal

response to these factors (66). There is a distinct group of women who suffer from

preeclampsia even when there is sufficient placental implantation. These women exhibit an

17

exaggerated response to the low-levels of inflammatory stimuli that are present in a normal

pregnancy. Maternal response may be excessive in women who are genetically more

sensitive to inflammatory signals, or in women with certain preexisting medical conditions

such as obesity, diabetes, or chronic hypertension (66,67).

2.4.1 The role of the immune system in preeclampsia

The immunogenic maladaptation theory is a popular theory used to explain the underlying

disease mechanisms of preeclampsia. According to this theory, immunogenic tolerance by

the mother to the antigens of her fetus is essential for a normal pregnancy. When immune

tolerance is not properly established, cytotrophoblast cells are unable to effectively invade

the uterine wall, causing poor placentation and a cascade of events that results in

preeclampsia.

There is strong epidemiological evidence to support this theory. Preeclampsia is often

referred to as the “disease of first pregnancies”, because previous pregnancies (68,69), and to

some extent previous abortions (70-72), are highly protective against preeclampsia. This

protective effect is largely lost if there is a change in partner in a subsequent pregnancy (73-

18

75). This seems to suggest that immunologic tolerance to fetal antigens established in a

woman’s first pregnancy is protective in subsequent pregnancies with the same partner.

Immunologic tolerance to fetal antigens may also be established prior to conception through

exposure to the sperm of the partner who will father her child. Protracted exposure to the

sperm of a consistent partner prior to conception has been shown to be protective against

preeclampsia. Studies have shown that women who use a method of contraception that

prevents sperm exposure are at greater risk of developing preeclampsia when they become

pregnant (76-78). An inverse relationship between risk of preeclampsia and duration of

sexual cohabitation has also been established (79,80). Furthermore, donor sperm

insemination represents a situation where the female is naive to sperm antigens, which may

explain the high risk of preeclampsia in these cases (81,82). Similarly, women who conceive

using donor oocytes and donated embryos are far more likely to develop preeclampsia. In

these cases, the developing fetus is genetically unrelated to the mother. The lack of prior

exposure to these antigens may impede the induction of immune tolerance necessary for a

normal pregnancy (82,83).

19

2.4.2 Preeclampsia in HIV positive women

Studies have shown that, prior to the advent of HAART, HIV positive women had a lower

risk of preeclampsia than the general population (11,84).

In a review, Wimalasundera and colleagues postulated that women with untreated HIV are

protected from preeclampsia as a result of their immunocompromised state. The authors

suggest that these women are unlikely to mount an exaggerated inflammatory response in

pregnancy due to the immune suppression associated with the progressive loss of CD4+ T-

lymphocytes in the disease (11).

Following from this theory, HAART treatment increases an HIV positive woman’s risk of

preeclampsia by restoring levels of her T lymphocytes. This restoration enables the pregnant

woman to respond, sometimes in an exaggerated manner, to foreign fetal antigens, thus

reinstating the pathological process that results in preeclampsia. Immune-dependant diseases

such as viral hepatitis, cytomegalovirus retinitis, and disseminated mycobacterial infections,

which also increase in frequency in patients following treatment with HAART, support this

theory (11).

20

On the other hand, Mawsen proposed that HAART increases risk of preeclampsia not by

immune restoration, but rather by a direct toxic effect on the liver (85). It was suggested that

synthesis and secretion of retinol-binding proteins are impaired due to HAART medication.

This leads to a reduction in serum retinol concentrations, which is associated with

preeclampsia. Retinoids pass from the mother’s liver into fetal circulation, leading to

hypervitaminosis A and is linked with adverse outcomes in preeclampsia.

Lastly, there is some evidence to suggest a link between HAART and the development of

insulin resistance (61-63). Since insulin resistance is a known risk factor for the development

of preeclampsia, it is possible that the mechanism of preeclampsia in HIV positive women on

HAART is mediated through insulin resistance rather than immune restoration.

2.5 Known risk factors for preeclampsia

Knowledge of risk factors for preeclampsia is important clinically. They enable the clinician

to target groups of patients at high risk of preeclampsia, and monitor them closely for signs

and symptoms to ensure early detection and treatment.

21

Maternal risk factors

• Primiparity

• New paternity

• Young maternal age and teenage pregnancy

• Advanced maternal age

• Limited exposure to partner’s sperm prior to pregnancy (e.g. short length of sexual

relationship, use of barrier method, donor insemination)

• Oocyte or embryo donation

• History of previous preeclampsia

• Family history of preeclampsia

• Black race

Paternal risk factors

• Partner fathered a preeclamptic pregnancy in another woman

• Partner was born of a preeclamptic pregnancy

Underlying/chronic disorders

• Chronic hypertension

• Renal disease

• Obesity

• Insulin resistance

• Gestational diabetes, diabetes mellitus

• Activated protein C resistance

• Periodontal disease

• Urinary Tract Infection in pregnancy

Behavioral factors

• Smoking (risk reduction)

• Cocaine and methamphetamine use

22

Environmental

• Elevated altitude

Pregnancy associated risk factors

• Multiple fetal gestation

• Hydrops fetalis

• Hydatidiform moles

• Chromosomal anomalies (trisomy 13, triploidy)

• In-utero diethylstilbestrol exposure

23

Literature Review

To date, there have been five cohort studies and one cross-sectional study conducted

exploring the link between HAART and preeclampsia.

The first study to examine the risk of preeclampsia in HIV positive women on HAART was a

matched cohort study conducted in 2002 by Wimalasundera and colleagues (11). The

investigators compared the risk of preeclampsia among HIV positive women on HAART,

HIV positive women on mono- or dual antiretroviral therapy, untreated HIV positive women,

and HIV negative controls. The investigators found the rate of preeclampsia in women on

HAART (11%) was significantly higher than untreated HIV positive women (0%) or women

who were on mono or dual antiretroviral therapy (1%). However, there was no significant

difference in rate of preeclampsia between HIV positive women treated with HAART and

HIV negative controls (11% vs. 14%; p=0.2).

In 2004, Matter and colleagues published results from another matched cohort study,

demonstrating that HIV positive women had a significantly lower risk for preeclampsia than

24

the HIV negative controls in their cohort (0.8% vs. 10.6%; p=0.0017) (19). Unfortunately,

they did not separate women based on type of antiretroviral therapy-- 78% of their cohort

was on HAART and the remaining 22% on monotherapy.

Suy and colleagues released results from the largest cohort study conducted on this topic in

2006. When they examined the incidence of preeclampsia in 82 HIV positive cases and 8,686

controls, their results revealed a conclusion opposite from that of Matter’s study. They found

that that the risk for preeclampsia in HIV positive women was significantly higher than the

general population (11.0% vs. 2.9%, p<0.001) (13). When they examined a historical cohort

of 472 HIV positive women, they found that HIV infection and initiation of HAART in the

first trimester were independent risk factors for developing preeclampsia after adjusting for

age, race, smoking, parity, multiple pregnancy and drug abuse.

Boer and colleagues reported results from a small matched cohort study examining the risks

of several fetal and maternal outcomes; preeclampsia was one of the outcomes being

examined. They concluded that there was no significant difference in the risk of

preeclampsia between HIV positive cases and HIV negative controls (2% vs. 1%).

25

In 2009, Haeri and colleagues reported results from another matched cohort study examining

the risks of many different fetal and maternal outcomes in women on HAART; again,

preeclampsia was one of the outcomes. They found that HIV positive women had

significantly lower rate of preeclampsia (6% vs. 12%, p=0.04); however this difference was

not significant when they adjusted for smoking and cocaine use in their population (Adjusted

OR 0.55, 95% CI 0.26-1.2).

Lastly, Kourtis and colleagues conducted a nation-wide cross-sectional study looking at a

random sample of 6000 inpatient hospitalizations in the United States (21). They reported no

difference in the hospitalization rates for preeclampsia between HIV positive pregnant

women and HIV negative pregnant women. While the sample size was a considerable

strength of this study, there were also significant limitations with its design. For example,

hospital coding was used to identify outcomes rather than diagnostic tests and features. The

authors admit that coding is often influenced by other factors such as reimbursement policies,

or differential practices in treating different populations. The hospital code they used for

identifying preeclampsia was a code for “hypertension complicating pregnancy”. This is a

loosely defined outcome, which is less specific than the definition of preeclampsia used in

other studies. Moreover, information on race, smoking, parity, and obesity were not

26

available, rendering the comparison populations potentially different in aspects that cannot

be accounted for. Similar to the study by Suy and colleagues, no treatment information is

available in the Kourtis study; investigators assumed that the majority of pregnant women

were on HAART.

Finally, in addition to the studies discussed above, three cohort studies from South Africa

found no difference in the rate of preeclampsia between HIV positive and HIV negative

pregnant women (86-88). However, HAART was not the standard of care for these cohorts,

and the majority of the women were either not receiving HAART or no treatment

information was available, making it difficult to assess the risk of preeclampsia in women

who are treated with HAART.

First author, year

Country Design Cases/controls or cohort size

Adjustment or matching

Main Findings: Risk of preeclampsia

Wimala-sundera, 2002 (11)

United Kingdom

Matched cohort

N= 428 214 HIV+ women 214 HIV– women

Age, parity, ethnicity - Higher risk in treated HIV positive women than untreated HIV positive women - No difference in risk between treated HIV positive women and HIV- negative controls

27

Table 3.1 Studies examining the risk of preeclampsia in HIV positive pregnant

women

Taken together, the literature on the association between HIV treated with HAART and

preeclampsia is largely inconclusive. This study will contribute to the literature, and may

help clarify the relationship between the two. We also feel it will be useful for local

clinicians to know the risk of preeclampsia in the patient population in Toronto. The results

from studies conducted in other countries may not be externally valid. Incidence of

Boer, 2006 (20)

Netherlands Matched cohort

N= 294 98 HIV+ women 96 HIV– women

Age, parity, ethnicity, Multiple pregnancy, Date of expected delivery

- No difference in risk between treated HIV positive women and HIV negative controls

Haeri, 2009 (22)

United States Matched cohort

N= 453 151 HIV+ women 302 HIV– women

Age, parity, ethnicity, Year of delivery, Insurance type, Hospital location, Mode of delivery, Drug abuse, Tobacco use, Co-morbidities (e.g. chronic hypertension)

- No difference in risk between treated HIV positive women and HIV negative women when tobacco and cocaine use were adjusted for

Mattar, 2004(19)

Brazil Cohort N= 1,900 123 HIV + women 1,708 HIV– women

Age, parity, ethnicity - Lower risk in treated HIV positive women compared to HIV negative women

Suy, 2006 (13)

Spain Cohort N=9,240 82 HIV + women 8,686 HIV - women

Age, parity, ethnicity, Multiple pregnancy, Tobacco use, Drug abuse

- Higher risk in HIV positive women compared to HIV negative women

Kourtis, 2006 (21)

United States Cross-sectional

N = 4,513,890 HIV+ women: 6,143 in 1994, 6,235 in 2003 HIV– women: 4,283,347 in 1994, 4,507,655 in 2003

Age, Insurance type, Hospital location, Drug abuse, Anemia, Urinary tract infection, Sexually transmitted infections, Clinically relevant co-morbidities

- No difference in hospitalization rates for preeclampsia between HIV positive women (no treatment information) and HIV negative women

28

preeclampsia differs considerably between populations, as it is influenced by genetic,

nutritional and environmental factors. The baseline risk of preeclampsia in the cohorts

discussed above ranged from 1% in the Netherlands to 12% in the United States. This

variation in incidence makes it difficult to compare risks between populations.

Pre-existing conditions such as renal disease and chronic hypertension represent significant

risk factors in the development of preeclampsia. These important risks factors were dealt

with differently in each study. For example, Wimalasundera and colleagues excluded women

with pre-existing conditions, while Kourtis and colleagues adjusted for clinically relevant

comorbidities in the multivariate analysis. Other studies provided no information on pre-

existing conditions in their cohorts.

Several of the previous studies did not have a 100% HAART use in their cohorts, clouding

the interpretation of their results. HAART use was sometimes assumed based on what was

considered to be routine care, or women on HAART were combined with women on mono

or dual antiretroviral therapies. Subgroup analysis in the Wimalasundera study indicates that

the risk of preeclampsia between women on HAART and women on mono or dual

antiretroviral therapies varies significantly (11% vs. 1%). Thus, separating the groups by

type of therapy is important for risk analysis.

29

As an improvement over some of the studies discussed above, we decided to control for

potentially confounding pre-existing conditions in this study, as well as exclude women who

were not treated with HAART.

Methods

30

This research is a retrospective, matched cohort study. The exposure variable is HIV

infection treated with HAART. A cohort of HIV positive pregnant women receiving

HAART, was compared to a matched cohort of HIV negative pregnant women.

The primary outcome was the development of preeclampsia and the secondary outcomes

were preterm delivery (PTD), low birthweight (LBW), and small for gestational age (SGA)

births of infants born from the women in the cohort.

The primary question was whether optimally treated HIV positive pregnant women are at

higher risk of developing preeclampsia than HIV negative pregnant women.

Secondary questions include whether HIV positive pregnant women treated with HAART

are at higher risk of giving birth to an infant who is preterm, LBW, or SGA births.

Ethics approval was received from Mt. Sinai Hospital Research Ethics Board as well as the

University of Toronto Research Ethics Board.

31

4.1 Population of interest and sampling methods

The cohorts were assembled at Mt. Sinai Hospital, a major referral centre for high-risk

pregnancies in Toronto. First, the HIV positive cohort was identified using the obstetric

database at Mt. Sinai Hospital. The electronic database includes basic information on all

women who gave birth at Mt. Sinai Hospital, a major referral centre for high-risk

pregnancies in Toronto. It contains each woman’s health record number, maternal age at

delivery, gravidity, parity, gestational age at delivery, date of delivery, number of fetuses

born at delivery, maternal HIV status at delivery along with a small amount of additional

information.

All consecutive HIV positive women in the database who satisfied the inclusion criteria were

included in the HIV positive cohort.

Inclusion criteria were women who:

• Received prenatal care at Mt. Sinai Hospital

• Were diagnosed with HIV prior to pregnancy or during antenatal screening

• Received HAART during the pregnancy

• Gave birth between January 1st, 2003 and January 15th, 2010

32

• Gave birth after 20 weeks gestation

Women who did not receive adequate antenatal care, or were not on HAART during

pregnancy were excluded from the study. HAART was defined as the concomitant use of at

least three antiretroviral medications.

To prevent including a subject twice, we examined only the first pregnancy of a woman if

she had more than one pregnancy in the study period. For multiple-fetal pregnancies, we

only included the outcomes of the first-born twin. This was done to ensure that fetal

outcomes resulting from multiple pregnancies are not overrepresented in the analysis.

Pregnancies that ended in a birth after at least 20 weeks gestation were included because

signs and symptoms of preeclampsia usually develop after 20 weeks.

Once the HIV positive cohort was assembled, a matched HIV negative cohort was

constructed using the same obstetrical database at Mt. Sinai Hospital. Age, parity and

number of fetuses were chosen as matching variables because they are very important factors

in the development of preeclampsia. Women were also matched based on year of delivery

33

because prescribing practices and prenatal management has changed slightly over the seven-

year study period.

The matched HIV negative women were randomly generated from the computer database.

Each HIV positive woman was matched to three HIV negative women who delivered in the

same year, had the same parity, were the same age at delivery (or within three years), and

gave birth to the same number of fetuses.

4.1.1 Selection bias

A challenge that had to be addressed is the inherent differences between the HIV positive

cases and HIV negative controls. Race, illicit drug use, smoking and socioeconomic status

are important sources of susceptibility bias in this study. For example, black race and cocaine

use have been established as risk factors for preeclampsia, LBW and SGA infants. A higher

proportion of women in the HIV positive cohort who are black or using cocaine could

systematically skew the data, suggesting a positive association between HIV and adverse

pregnant outcomes, when one may not exist.

34

To minimize bias, information was collected on race, smoking status, illicit drug use, and

clinically relevant diagnoses (e.g. diabetes, chronic hypertension, renal disease, obesity) so

that they could be controlled for in the data analysis. Information on medical conditions was

found in patients’ prenatal records. To identify obesity, the women’s BMI was calculated

using pre-pregnancy weight and height. A BMI equal to or greater than 30 kg/m2 was

considered obese.

4.1.2 Sample size

Through sample size determination, it was calculated that 91 cases and 273 controls (case:

control ratio of 1:3) would be sufficient to detect a 2-fold increase in preeclampsia. This will

be equivalent to a relative risk of 2 with 80% power and alpha of 0.05 for estimating

statistical significance.

4.2 Data collection

35

Demographic data, information on HAART use, risk factors and pregnancy outcomes were

ascertained through detailed review of prenatal records and inpatient admission history from

the medical records at the Mt. Sinai Hospital. Data was inputted directly into an electronic

database that was created in Microsoft Excel. See appendix for a copy of the database.

To quantify exposure to HAART, information was collected on which antiretroviral drugs

the HIV positive women were taking during pregnancy. If her regimen was switched at some

point in the pregnancy, the combination of drugs used closest to her delivery was recorded.

Also recorded was the date of HAART initiation, so that the length of HAART exposure was

known.

To determine the presence of symptoms related to preeclampsia, information regarding the

measurement of urine protein, platelet counts and liver enzymes as well as qualitative

symptoms such as visual disturbances or severe epigastric pain was recorded.

36

4.3 Outcomes

4.3.1 Primary Outcome: Preeclampsia

Preeclampsia is part of a spectrum of hypertensive disorders in pregnancy. It often presents

as a syndrome of maternal and fetal symptoms, and the clinical manifestations can be very

heterogeneous. Over the decades, there have been a number of definitions promoted by

experts and representative bodies for the purpose of diagnosing preeclampsia. To avoid

classification bias, a definition of preeclampsia was selected, and adhered to firmly for all

subjects in the study.

The diagnostic criteria chosen for preeclampsia is consistent with criteria published by The

American National Working Group on High Blood Pressure in Pregnancy (89), the American

College of Obstetricians and Gynecologists (90), and the International Society for the Study

of Hypertension in Pregnancy (ISSHP) (91). According their classification system,

preeclampsia is a combination of hypertension after 20 weeks gestation, and new-onset

proteinuria. Hypertension is defined as > 140 mmHg systolic blood pressure and/or >90

mmHg diastolic blood pressure. Proteinuria is defined as urine protein greater than or equal

to 0.3 g per 24-hour urine test, which usually corresponds to 1+ on a dipstick urine test.

37

Preeclampsia was considered to be severe when one or more of the following criteria were

present: proteinuria of 5 g or higher in a 24-hour urine specimen, cerebral or visual

disturbances, epigastric or right upper quadrant pain, impaired liver function,

thrombocytopenia or fetal growth restriction (90,91). Thrombocytopenia is defined as <100

000 cells/mm3, and impaired liver function is defined as elevated hepatic enzymes as

>36uL/mmol of alinine- or aspartate- aminotransferase enzymes (ALT or AST).

Recently, the use of proteinuria has been called into question for the definition preeclampsia.

Some representative bodies, such as the Australasian Society for the Study of Hypertension

in Pregnancy (ASSHP) (92), and the Society of Obstetricians and Gynecologists of Canada

(SOGC) (93) have suggested that insisting on proteinuria to make a diagnosis of

preeclampsia is too restrictive. According to their classification, preeclampsia should be

diagnosed when there is gestational hypertension in combination with at least one end-organ

dysfunction.

The advantage of this definition is that it is more sensitive, and can be valuable in clinical

obstetrics where it is important to ensure that all women who are at risk of adverse outcomes

are identified. However, from a research perspective a more stringent definition is

38

preferable, such that only women with the definite disease are studied. For this reason, the

more restrictive and specific definition promoted by the ISSHP was chosen for this study.

4.3.2 Secondary outcomes: Preterm birth, Low birthweight, Small for gestational

age

Secondary outcomes were obtained from delivery records at Mt. Sinai Hospital.

Low birthweight was defined as a baby weighing less than 2,500 g at birth. Small for

gestational age was defined as any baby weighting less than the 10th percentile for his or her

gestational age (94). Preterm birth was defined as an infant born before 37 weeks gestational

age. Gestational age was determined from the first day of the last menstrual period and/or a

dating ultrasound.

4.4 Data Analysis

Data were analyzed using SPSS software. Chi square tests were used to conduct univariate

comparisons of categorical variables and independent samples t tests were used to compare

group means. A p value < 0.05 was considered statistically significant.

39

To further examine the relationship between HIV status and perinatal outcomes, a stepwise

backwards multivariable logistic regression model was constructed to adjust for covariates

that differed significantly between the two cohorts. Variables with significance level p<0.15

in univariate analyses were included in multivariable model.

Adjusted odds ratios and 95% confidence intervals were calculated to describe the risk of the

primary and secondary outcomes in the cohort after controlling for necessary covariates.

40

Results

Table 5.1 Maternal Demographics

Maternal age and parity were similar between HIV positive and HIV- negative women,

indicating that matching on these two variables was successful.

The ethnic breakdown between the two groups differed significantly. The majority (75%) of

the HIV positive cohort consisted of black women of African or Caribbean decent, and only

6.8% were Caucasian. In contrast, the majority (69%) of the HIV negative cohort consisted

of Caucasian women, and only 10.7% were black.

HIV positive

n=91

HIV negative n=273

p value

Mean Age (+SD) 31.0 (+4.8) 31.0 (+4.7) 0.94

Mean Parity (+SD) 1.1 (+1.3) 1.2 (+1.4) 0.72

Race

Caucasian 6.8% 69.0%

Black 75.0% 10.7%

Other 18.2% 20.2%

<0.01

* SD= standard deviation

41

Table 5.2 Presence of Risk Factors

Presence of comorbidites and risk factors were similar between HIV positive and HIV

negative women, e rtxcept for race (75% vs. 10.7% black race; p<0.01) and cocaine use

(4.4% vs. 0.4%; p<0.01) in the HIV positive cohort.

HIV positive

n=91

HIV negative n=273

p value

Multiple Gestation Pregnancy 3.3% 3.3% 1.00 Primiparity 45.1% 45.1% 1.00 Black race 75.0% 10.7% <0.01 Chronic hypertension 4.4% 4.0% 0.88 Renal Disease 1.1% 1.1% 1.00 Diabetes Mellitus 7.7% 5.5% 0.45 UTI 5.5% 4.8% 0.78 History of Preeclampsia 0.0% 1.5% 0.25 Obese (BMI>30kg/m2) 16.1% 15.2% 0.85 Mean BMI (+SD) 25.9 (+6.9) 25.0 (+6.1) 0.32 Current smoker 9.9% 5.1% 0.11 Current cocaine use 4.4% 0.4% <0.01

* SD= standard deviation

42

Table 5.3 HAART initiation and viral load of HIV positive cohort

On HAART prior to conception (% of HIV positive cohort) 40.0% Median gestational age (weeks) of HAART initiation for women who started HAART during pregnancy

19.07

Viral load at delivery (% of HIV positive cohort) Undetectable / <50 counts per million 80.0 % 50- 1 000 cpm 14.6 % > 1 000 cpm 5.6 %

Forty percent of women from the HIV positive cohort were already on HAART prior to

conception. The remaining half of the cohort was initiated on HAART in the second or third

trimester of pregnancy, with the median gestational age of HAART initiation being 19

weeks.

The majority of the cohort (80%) had an undetectable viral load count, indicating that most

women were stable on their medication and effectively suppressing the HIV virus.

43

Table 5.4 HIV Medications

Proportion of HIV

positive cohort Nucleoside Reverse Transcriptase Inhibitor (NRTI) 96.7% Combivir (ziduvodine + lamivudine) 67.8% Kivexa (abacavir + lamivudine) 14.4% 3 TC (lamivudine) 6.7% Trizivir (ziduvodine + lamivudine+ abacavir) 5.6% Viread (tenofovir) 4.4% Zerit (stavudine) 4.4% Ziagen (abacavir) 3.3% Retrovir (zidovudine) 2.2% Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI) 20.0% Viramune (nevirapine) 20.0% Protease Inhibitor (PI) 75.6% Kaletra (lopinavir/ ritonavir) 44.4% Viracept (nelfinavir) 22.2% Reyataz (atazanavir) 5.6% Norvir (ritonavir) 4.4% Telzir (fosamprenavir) 2.2% Agenerase (amprenavir) 1.1% Fortovase (saquinavir soft gel capsules) 1.1%

44

Table 5.5 Maternal Outcomes

HIV

positive n=91

HIV negative n=273

Unadjusted Odds Ratio

p value

Preeclampsia 3.3%

(n=3) 5.1%

(n=14) 0.63 0.58

Severe preeclampsia 3.3% (n=3)

3.3% (n= 9)

1.00

Thrombocytopenia 5.5% 1.5% 0.03 Elevated LFT, % of cohort 13.2% 5.1% 0.01 Elevated LFT, % of women who were tested

25.5% 25.6% 0.99

Mean AST (+SD) 95.9 (+381.8)

35.4 (+36.2)

Mean ALT (+SD) 71.6 (+265.1)

28.2 (+39.1)

Preeclampsia occurred in 3.3% (3/91) of the HIV positive cohort , and 5.1% (14/273) of the

HIV negative cohort. The difference in risk was not significantly different (p=0.58). The

unadjusted odds ratio of developing preeclampsia was 0.63 for HIV positive women

compared to HIV negative women.

All three HIV positive women who developed preeclampsia experienced a severe form of the

disease, while nine out of 14 HIV negative preeclampsia cases had severe preeclampsia.

*SD= standard deviation

45

However, the rate of severe preeclampsia within each cohort was not statistically

significantly different.

A low platelet count of less than 100 000 cells/mm3, thrombocytopenia, was significantly

higher in the HIV positive cohort compared to the HIV negative cohort (5.5% vs. 1.5%;

p=0.03).

Significantly more women in the HIV positive cohort were diagnosed with elevated liver

enzymes compared the HIV negative group (13.2% vs. 5.1%; p= 0.01). However, 54% of the

HIV positive cohort was screened for elevated liver enzymes, whereas only 21% of the HIV

negative cohort was screened. In both cohorts, approximately 26% of women who were

screened where diagnosed with elevated liver enzymes.

46

Table 5.6 Fetal Outcomes

Fetal outcomes were affected in the HIV positive cohort across all measurements, including

premature birth, low birthweight, and small for gestational age. However, the significant

differences were low birthweight (20.2% vs. 9.9%; OR= 2.31; p=0.01), and small for

gestational age (20.2% vs. 8.8%; OR= 2.63; p<0.01). Rate of preterm birth did not differ

significantly between cohorts (15.6% vs. 11.4%; OR=1.44; p=0.29).

HIV positive

n=91

HIV negative n=273

Unadjusted Odds Ratio

p value

Birth Gestational Age (+SD) 38.3 (+3.1)

38.7 (+2.8)

0.34

Preterm birth (<37weeks) 15.6% 11.4% 1.44 0.29 Birthweight (+SD) 2946.7

(+707.7) 3260.0

(+688.2) <0.01

Low birthweight (<2, 500 g) 20.2% 9.9% 2.31 0.01 Very low birthweight (<1, 500 g) 4.5% 2.9% 0.47 Small for gestational age (<10th percentile)

20.2% 8.8% 2.63 <0.01

Intrauterine death 2.2% 0.4% 0.09

Neonatal death 1.1% 1.8% 0.64

*SD= standard deviation

47

Table 5.7 HIV positive women who developed preeclampsia

Patient 1 Patient 2 Patient 3 Race Caucasian Black Other Plurality multiple singleton singleton Parity 0 0 2 Age 30 32 25 Chronic hypertension No No Yes Renal disease Yes No No Diabetes No No No History of preeclampsia No No No Smoker No No No Cocaine use No No No Obese No No No Hypertension 176/82 144/87 142/105 Proteinuria 3.03g/24 hr

3+ dipstick 2+ dipstick 2+ dipstick

Platelet count 125, 000 31, 000 127, 000 AST 60 2680 165 ALT 23 1810 22 End-organ dysfunction/ adverse effects

• HELLP • Epigastric pain • IUGR

• Clonus & hyperreflexia

• Abruptio placenta • Edema

Viral load (counts per million)

<50 cpm <50 cpm <50 cpm

HAART initiation 18 weeks prior to conception prior to conception

Antiretroviral Drugs Nucleoside analog reverse transcriptase inhibitor (NRTI)

3TC od Retrovir (AZT)

od

Kivexa od (abacavir + lamivudine)

Combivir bid (3TC+ AZT)

Protease Inhibitor (PI)

Viracept bid Fortovase, 2 tabs bid

Viracept bid

Three HIV positive women developed preeclampsia. All three women were stable on

HAART and had undetectable viral loads. All three women were on protease inhibitor

containing antiretroviral regimens.

48

Patient 1 and patient 3 were both at risk of preeclampsia due to preexisting risk factors (renal

disease and chronic hypertension).

All three cases of preeclampsia met the definition of severe preeclampsia. Patient 1 had

severe proteinuria (>3.0g/24 hrs), and elevated AST (60 uL/mmol). Patient 2 had hemolysis,

critical levels of AST and ALT (2680 and 1810uL/mmol), severe thrombocytopenia (31,000

cells/mm3), and epigastric pain. Patient 3 had elevated ALT (165 uL/mmol), as well as

clonus and hyperreflexia.

49

Table 5.8 Adjusted Comparison of Outcomes

HIV

positive n=91

HIV negative n=273

Unadjusted OR

Adjusted OR*

95% CI

Maternal outcome Preeclampsia 3.3% 5.1% 0.63 0.59 0.11, 3.08 Neonatal outcomes Low birth weight 20.2% 9.9% 2.31 2.91 1.47, 5.78 Preterm birth 15.6% 11.4% 1.44 1.70 0.79, 3.66 Small for gestational age

20.2% 8.8% 2.63 2.08 0.89, 5.24

* Adjusted Odds Ratios from multivariable logistic regression model including race,

cocaine use and smoking status

Backwards-stepwise regression models were built for the primary and secondary outcomes to

adjust for potentially confounding covariates. HIV status, race, smoking status and cocaine

use were included in the models, as these covariates differed with a p <0.15 between the HIV

positive and HIV negative groups. After adjusting for race, smoking and cocaine use, HIV

status remained a significant predictor of LBW, (AOR= 2.91; 95% CI 1.47, 5.78). While

SGA was significantly different between the two cohorts in the univariate analysis, HIV was

not a significant predictor of this outcome (AOR=2.08; 95% CI 0.89, 5.24) after adjusting for

race, smoking and cocaine use. The link between HIV and SGA was confounded by race and

smoking which were both predictors of SGA in the final model.

50

HIV remained a non-significant predictor for preeclampsia (AOR= 0.59; 95% CI 0.11, 3.08)

and preterm birth (AOR= 1.70; 95% CI 0.79, 3.66) after adjusting for race, smoking and

cocaine use.

51

Discussion

6.1 Primary Outcome

In the final analysis, the risk of preeclampsia did not differ significantly between HIV

positive women on HAART (3.3%) and HIV negative women (5.1%). A non-significant

difference in risk of preeclampsia corroborates the finding of other studies on this topic, and

is a reassuring finding for both patients and providers (11,20-22).

Moreover, two out of the three HIV positive women who developed preeclampsia had well-

established risk factors for the disease. One woman was carrying multiples and had renal

disease, while the other had chronic hypertension. This supports the notion that HIV

infection and HAART does not independently predispose women to developing

preeclampsia.

The initial hypothesis was that HIV positive women receiving HAART have an increased

risk of preeclampsia. The data not only disproves this hypothesis, but also reveals a lower

52

rate of preeclampsia for the HIV positive women as compared to HIV negative women,

though the decreased risk is not statistically significant. Wimalasundera (2002), Haeri (2009)

and Matter (2004), all reported similar findings. A summary of the results is below.

HIV positive

HIV negative Significant?

Wimalasundera et al. (2002)

11% 14% - Not significant

Haeri et al. (2009) 6% 12% - Significant before adjusting for smoking and cocaine use

Matter et al. (2004) 0.8% 10.6% - Significant (p<0.01)

Current thesis (2010) 3.3% 5.0% - Not significant

Based on this data, HIV infection treated with HAART is not a risk factor for the

development of preeclampsia. In fact, the data may even suggest that HIV is protective;

however more research must be done to confirm this. The current immunological theory on

preeclampsia proposes that a weak immune system in HIV positive women may be

protective against preeclampsia. While HAART restores immunological parameters,

complete immune function may not be completely recovered. Another possibility is that HIV

infection may inhibit other factors that play a relevant role in preeclampsia development

(19). However, the pathogenesis of preeclampsia is still being elucidated, thus the possible

mechanism is unknown.

53

While the conclusion that there is no risk difference for preeclampsia between HIV positive

and HIV negative women is consistent with most of the literature on this topic, it conflicts

with the results from the largest cohort study examining this research question. The study,

conducted by Suy and colleagues, concluded that HIV positive women had a much higher

incidence of preeclampsia (11.0%) than the general population (2.9%). A possible

confounder that could explain the high rate of preeclampsia in Suy’s cohort is that 31% of

their cohort consisted of current injection drug users (though the authors tried to adjust for

this in the analysis), whereas our cohort had no injection drug use. Injection drug use is not

an independent risk factor for developing preeclampsia; however, it is a strong marker of

socioeconomic status and could contribute to poor outcomes in pregnancy. Other possible

confounders could include medical conditions that contribute to preeclampsia. Chronic

hypertension and diabetes are known risk factors in preeclampsia. These were found to be in

low prevalence in our study. Suy and colleagues did not record any statistics on their

population’s underlying medical conditions; therefore we are unable to compare our cohorts.

Although the rate of preeclampsia was lower in the HIV positive cohort, HIV positive

women experienced two cardinal symptoms of preeclampsia -- elevated liver enzymes and

thrombocytopenia -- more often than HIV negative women. Rate of thrombocytopenia in the

54

HIV positive cohort was 5.5%, which was significantly higher than the rate in the HIV

negative cohort (1.5%). The proportion of women in the HIV positive cohort who were

diagnosed with elevated liver enzymes (13.2%) was also significantly higher than the

proportion of HIV negative women who received the diagnosis (5.1%). Unfortunately, it is

unclear from the data whether the latter finding is the result of screening bias. 54% of the

HIV positive cohort was screened for elevated liver enzymes, whereas only 21% of the HIV

negative cohort was screened. In both cohorts, approximately 26% of women who were

screened were diagnosed with elevated liver enzymes. It is possible that a higher proportion

of the HIV positive cohort was diagnosed simply because they were tested more often.

Alternatively, it is possible that physicians screened more often as more HIV positive women

were symptomatic and therefore a greater proportion of the HIV positive cohort did in fact

have elevated liver enzymes.

Increases in aspartate transaminase (AST) and alanine transaminase (ALT) liver enzymes

levels have been associated with nevirapine (NVP) containing HAART regimens (95).

However only 2 out of the 12 HIV positive women who were diagnosed with elevated liver

enzymes were on HAART regimen that included NVP. Future research should aim to

55

develop a greater understanding into the hepatotoxicity of HAART during pregnancy, and

any morbidity associated with elevated liver enzymes levels.

Since clinical manifestations of severe preeclampsia, such as elevated liver enzymes and

thrombocytopenia, were relatively common in HIV positive women, it is not surprising that

all three HIV positive women who developed preeclampsia experienced “severe

preeclampsia”. This finding is consistent with the findings by Wimalasundera and

colleagues. They remarked that the HIV positive women who developed preeclampsia in

their cohort usually experienced severe cases of the disease.

More research must be done to further examine this observation. It is possible be that HIV

positive women who develop preeclampsia experience a severe form of the disease due to

their underlying HIV infection. Alternatively, it could mean that there is an overlap between

symptoms of preeclampsia and adverse side effects associated with HAART. This overlap of

symptoms could complicate the diagnosis and management of preeclampsia in HIV positive

patients.

56

The symptoms of elevated liver enzymes and thrombocytopenia are components of a severe

form of preeclampsia called HELLP (Hemolysis, Elevated Liver enzymes, and Low

Platelets). Women with HELLP should be monitored closely during pregnancy and often

require early delivery. HIV positive women may be at a greater risk of developing HELLP

than the general population. While this research question was beyond the scope of this study,

it should be explored in future research.

6.2 Secondary Outcomes

The rates of low birthweight and small for gestational age were significantly higher in the

HIV positive cohort compared to the HIV negative cohort. This is consistent with the results

of recent studies published on fetal outcomes of HIV positive, HAART-treated pregnancies.

The association between SGA and HIV infection was confounded by smoking and race, and

thus HIV was not a predictor for SGA once these factors were adjusted for. However, the

HIV positive cohort maintained higher risk for LBW (adjusted odds ratio 2.91) after

smoking, cocaine use and race were adjusted for. The risk of giving birth to a LBW infant for

HIV positive mothers could be due to HIV infection or to adverse effects of HAART.

However, risk of LBW can also be influenced by factors whose impact is difficult to

57

quantify, such as differences in socioeconomic status between the cohorts. Black race and

cocaine use, two possible markers of socioeconomic status, were adjusted for in the analysis.

Nonetheless, there may be other contributing factors; women with HIV may have inferior

nutrition during pregnancy, or may be physically unsafe, contributing to LBW babies.

Another possible contributor to LBW is the higher rate of preterm delivery in the HIV

positive cohort compared to the HIV negative cohort (15.6% vs.11.4%). This difference was

not statistically different, but this could be because our study was not sufficiently powered to

detect significance in this outcome. The fact that HIV status was not a significant predictor of

SGA supports the idea that the increased risk of LBW is due to the higher number of preterm

births. This is because SGA takes the gestational age into account when considering the birth

weight of the baby.

Unfortunately, information regarding whether women’s births were spontaneous or induced

was unavailable. It is possible that HAART increases risk of spontaneous preterm birth.

Alternatively, it is possible that physicians induced preterm labour more frequently in HIV

positive women. Reasons for induction are often due to medical concerns such as elevated

liver enzymes or severe preeclampsia.

58

It is important for clinicians treating HIV positive women to be aware of the increased risk of

LBW, given the morbidity and mortality associated with this outcome. Careful fetal

monitoring during pregnancy is indicated for this population.

6.3 Study Limitations

The limitations of this research are largely based in the observational design of the study,

because it is difficult to control for all possible confounding factors (both known and

unknown). Therefore, there may be differences between the two cohorts, which we cannot

control for (e.g. differences in diet, stress), that are contributing to the different rate of

outcomes. Several confounders were accounted for, however, either through matching (age,

parity, multiple pregnancy, year) or controlling in the data analysis (race, smoking, drug use).

In addition, there may be a referral bias in this study. Both HIV positive patients and controls

were chosen from Mt. Sinai, a referral centre specializing in high-risk pregnancies. HIV

positive pregnancies are by nature high-risk, and by choosing controls from the same

institution, high-risk pregnancies may have been over-selected in the control cohort. A

control group selected from Mt. Sinai may have a greater rate of adverse pregnancy

59

outcomes than a control group selected from a community hospital. This bias will attenuate

the relative risk of adverse pregnancy outcomes in HIV positive women.

Lastly, it is important to note that the study does not reveal the impact of HAART as an

independent exposure on perinatal outcomes. This is because the comparison group was HIV

negative women and not untreated HIV positive women. However, the study is still an

important evaluation of the perinatal outcomes in optimally-treated HIV positive women

compared to HIV negative women of similar age and parity.

60

Conclusion

This study shows that HIV positive women who undergo HAART during pregnancy do not

face a higher risk of developing preeclampsia than HIV negative women of similar age and

parity. While this is reassuring for both patients and providers, HIV positive women should

still be carefully monitored throughout pregnancy because data from this study suggests that

women on HAART face a higher risk of having elevated liver enzymes and low platelets –

two signs of severe preeclampsia/HELLP. Since hepatotoxicity has been associated with

some HAART regimens in the literature, it could simply mean that adverse effects of

HAART and clinical manifestations of severe preeclampsia/ HELLP overlap, making the

diagnosis and management of these women challenging.

Future research should focus on the apparent increased risk of elevated liver enzymes in HIV

positive pregnant women. Determining the significance of elevated liver enzymes in

pregnancy will be helpful in the management of women with elevated liver enzymes, and

may help clinicians decide whether early induction of labour is indicated in these cases.

61

In terms of fetal outcomes, HIV infection treated with HAART is associated with an

increased risk of LBW. Careful antenatal surveillance in HIV positive mothers is indicated,

and should include fetal growth assessment by ultra-sonography.

Overall, it is important for clinicians to be aware of the risk of elevated liver enzymes,

thrombocytopenia and LBW fetal outcomes in HIV positive women on HAART. However,

the overwhelming benefit of HAART in preventing perinatal transmission of HIV and

improving maternal health outweigh any of the apparent risks, and so treatment with

HAART should remain the standard of care.

62

Appendix

Data collection tool

Demographics Race

Plurality

Parity Age

Risk Factors

Chronic Hypertension Renal Disease Diabetes History of Preeclampsia Smoker Cocaine Use UTI Weight Height BMI Obese

Preeclampsia

Gestational Hypertension Urine Dipstick 24hrUrineValue Platelet Count AST ALT Abruptio placenta

63

Other signs or symptoms Preeclampsia Severe preeclampsia/ HELLP

Fetal Outcomes

EDC DOB Baby Gestational Age Premature Birthweight SGA Low Birthweight Apg1 Apg2 IUGR Stillbirth Neonatal death

Date of HAART initiation

HAART initiation (in GA)

Viral Load before delivery

Antiretroviral drugs

3 TC Agenerase Combivir Fortovase Kaletra Kivexa Norvir Retrovir Reyataz Telzir Trizivir Viracept Viramune Viread Zerit Ziagen

64

References

(1) Joint United Nations Programme on HIV/AIDS (UNAIDS), World Health Organization

(WHO). AIDS epidemic update : November 2009. 2009 November 2009.

(2) Public Health Agency of Canada. Summary: Estimates of HIV prevalence and incidence

in Canada, 2008. 2009:1-3.

(3) Gahir S, Anger GJ, Ibrahim M, Read S, Piquette-Miller M. Management of HIV positive

pregnancies in Ontario: current status. Can.J.Clin.Pharmacol. 2009 Winter;16(1):e68-77.

(4) Public Health Agency of Canada. HIV and AIDS in Canada. Surveillance Report to

December 31, 2008. 2009(12/23/2009):1-93.

(5) Dieudonne A, McIntryre JA, Fredonese F, Giaquinto C, Oleske JM. HAART IN HIV-

infected children: one decade later. In: Zuniga J, Whiteside A, Ghaziani A, Bartlett J, editors.

A Decade of HAART: The Development and Global Impact of Highly Actice Antiretroviral

Therapy New York: Oxford University Press; 2008. p. 63-82.

(6) De Cock KM, Fowler MG, Mercier E, de Vincenzi I, Saba J, Hoff E, et al. Prevention of

mother-to-child HIV transmission in resource-poor countries: translating research into policy

and practice. JAMA 2000 Mar 1;283(9):1175-1182.

(7) Public Health Agency of Canada. HIV and AIDS in Canada. Surveillance Report to

December 31, 2006. 2007:1-89.

(8) Connor EM, Sperling RS, Gelber R, Kiselev P, Scott G, O'Sullivan MJ, et al. Reduction

of maternal-infant transmission of human immunodeficiency virus type 1 with zidovudine

treatment. Pediatric AIDS Clinical Trials Group Protocol 076 Study Group. N.Engl.J.Med.

1994 Nov 3;331(18):1173-1180.

(9) Cooper ER, Charurat M, Mofenson L, Hanson IC, Pitt J, Diaz C, et al. Combination

antiretroviral strategies for the treatment of pregnant HIV-1-infected women and prevention

of perinatal HIV-1 transmission. J.Acquir.Immune Defic.Syndr. 2002 Apr 15;29(5):484-494.

(10) Rachlis AR, Zarowny DP. Guidelines for antiretroviral therapy for HIV infection.

Canadian HIV Trials Network Antiretroviral Working Group. CMAJ 1998 Feb

24;158(4):496-505.

65

(11) Wimalasundera. Pre-eclampsia, antiretroviral therapy, and immune reconstitution. The

Lancet infectious diseases 2002.

(12) European Collaborative S. Pregnancy-related changes in the longer-term management of

HIV-infected women in Europe. Eur.J.Obstet.Gynecol.Reprod.Biol. 2003 Nov 10;111(1):3-

8.

(13) Suy A, Martinez E, Coll O, Lonca M, Palacio M, de Lazzari E, et al. Increased risk of

pre-eclampsia and fetal death in HIV-infected pregnant women receiving highly active

antiretroviral therapy. AIDS 2006 January 2;20(1):59-66.

(14) Hacker NF. Hacker and Moore's essentials of obstetrics and gynecology. 5th ed. ed.

London: Saunders/Elsevier; 2010.

(15) Hypertension in pregnancy. New York: Marcel Dekker; 2003.

(16) McDonald SD, Malinowski A, Zhou Q, Yusuf S, Devereaux PJ. Cardiovascular

sequelae of preeclampsia/eclampsia: a systematic review and meta-analyses. Am.Heart J.

2008 Nov;156(5):918-930.

(17) Von Dadelszen P, Magee L. What matters in preeclampsia are the associated adverse

outcomes: the view from Canada. Curr.Opin.Obstet.Gynecol. 2008 Apr;20(2):110-115.

(18) Health Canada. Special Report on Maternal Mortality and Severe Morbidity in Canada

— Enhanced Surveillance: The Path to Prevention. 2004.

(19) Mattar R, Amed AM, Lindsey PC, Sass N, Daher S. Preeclampsia and HIV infection.

Eur.J.Obstet.Gynecol.Reprod.Biol. 2004 Dec 1;117(2):240-241.

(20) Boer K, Nellen J, Patel D, Timmermans S, Tempelman C, Wibaut M, et al. The AmRo

Study: pregnancy outcome in HIV-1-infected women under effective highly active

antiretroviral therapy and a policy of vaginal delivery. Br.J.Obstet.Gynaecol. 2007;114:148-

155.

(21) Kourtis AP, Bansil P, McPheeters M, Meikle SF, Posner SF, Jamieson DJ.

Hospitalizations of pregnant HIV-infected women in the USA prior to and during the era of

HAART, 1994-2003. AIDS 2006 Sep 11;20(14):1823-1831.

(22) Haeri S, Shauer M, Dale M, Leslie J, Baker AM, Saddlemire S, et al. Obstetric and

newborn infant outcomes in human immunodeficiency virus-infected women who receive

highly active antiretroviral therapy. Am.J.Obstet.Gynecol. 2009 Sep;201(3):315.e1-315.e5.

(23) Loutfy MR, Hart TA, Mohammed SS, Su D, Ralph ED, Walmsley SL, et al. Fertility

desires and intentions of HIV positive women of reproductive age in Ontario, Canada: a

cross-sectional study. PLoS One 2009 Dec 7;4(12):e7925.

(24) Wittman BK, Murphy KJ, King JF, Yuen BH, Shaw D, Wittman AG. Maternal

mortality in British Columbia in 1971-8611. Can.Med.Assoc.J. 1988;139:37-40.

66

(25) Collaborative Group on AIDS Incubation and HIV Survival. Time from HIV-1

seroconversion to AIDS and death before widespread use of highly-active antiretroviral

therapy: a collaborative re-analysis. The Lancet 2000;355(9210):1131-1137.

(26) Schneider MF, Gange SJ, Williams CM, Anastos K, Greenblatt RM, Kingsley L, et al.

Patterns of the hazard of death after AIDS through the evolution of antiretroviral therapy:

1984-2004. AIDS 2005;19(17):2009.

(27) Lorenzi P, Spicher VM, Laubereau B, Hirschel B, Kind C, Rudin C, et al. Antiretroviral

therapies in pregnancy: maternal, fetal and neonatal effects. Swiss HIV Cohort Study, the

Swiss Collaborative HIV and Pregnancy Study, and the Swiss Neonatal HIV Study. AIDS

1998 Dec 24;12(18):F241-7.

(28) European Collaborative S, Swiss Mother and Child HIV Cohort,Study. Combination

antiretroviral therapy and duration of pregnancy. AIDS 2000 Dec 22;14(18):2913-2920.

(29) Thorne C, Patel D, Newell ML. Increased risk of adverse pregnancy outcomes in HIV-

infected women treated with highly active antiretroviral therapy in Europe. AIDS 2004 Nov

19;18(17):2337-2339.

(30) Townsend CL, Cortina-Borja M, Peckham CS, Tookey PA. Antiretroviral therapy and

premature delivery in diagnosed HIV-infected women in the United Kingdom and Ireland.

AIDS 2007;21(8):1019.

(31) Martin F, Taylor GP. Increased rates of preterm delivery are associated with the

initiation of highly active antiretrovial therapy during pregnancy: a single-center cohort

study. J.Infect.Dis. 2007 Aug 15;196(4):558-561.

(32) Grosch-Woerner I, Puch K, Maier RF, Niehues T, Notheis G, Patel D, et al. Increased

rate of prematurity associated with antenatal antiretroviral therapy in a German/Austrian

cohort of HIV-1-infected women. HIV.Med. 2008 Jan;9(1):6-13.

(33) Machado ES, Hofer CB, Costa TT, Nogueira SA, Oliveira RH, Abreu TF, et al.

Pregnancy outcome in women infected with HIV-1 receiving combination antiretroviral

therapy before versus after conception. Sex.Transm.Infect. 2009 Apr;85(2):82-87.

(34) Cotter AM, Garcia AG, Duthely ML, Luke B, O'Sullivan MJ. Is antiretroviral therapy

during pregnancy associated with an increased risk of preterm delivery, low birth weight, or

stillbirth? J.Infect.Dis. 2006 May 1;193(9):1195-1201.

(35) Tuomala RE, Shapiro DE, Mofenson LM, Bryson Y, Culnane M, Hughes MD, et al.

Antiretroviral therapy during pregnancy and the risk of an adverse outcome. N.Engl.J.Med.

2002 Jun 13;346(24):1863-1870.

(36) Tuomala RE, Watts DH, Li D, Vajaranant M, Pitt J, Hammill H, et al. Improved

obstetric outcomes and few maternal toxicities are associated with antiretroviral therapy,

67

including highly active antiretroviral therapy during pregnancy. J.Acquir.Immune

Defic.Syndr. 2005 Apr 1;38(4):449-473.

(37) Szyld EG, Warley EM, Freimanis L, Gonin R, Cahn PE, Calvet GA, et al. Maternal

antiretroviral drugs during pregnancy and infant low birth weight and preterm birth. AIDS

2006 Nov 28;20(18):2345-2353.

(38) Schulte J, Dominguez K, Sukalac T, Bohannon B, Fowler MG, Pediatric Spectrum of

HIV Disease Consortium. Declines in low birth weight and preterm birth among infants who

were born to HIV-infected women during an era of increased use of maternal antiretroviral

drugs: Pediatric Spectrum of HIV Disease, 1989-2004. Pediatrics 2007 Apr;119(4):e900-6.

(39) Kourtis A, Schmid C, Jamieson D, Lau J. Use of antiretroviral therapy in pregnant HIV-

infected women and the risk of premature delivery: a meta-analysis. AIDS 2007 12

Mar;21(5):607-615.

(40) Low birth weight with nevirapine-based ART in Abidjan, Cote d’Ivoire: the ANRS

Ditrame Plus Cohort and MTCT-Plus Initiative, 2001 to 2007.

(41) Risk factors for adverse pregnancy outcomes among HIV-infected women in Gaborone,

Botswana. .

(42) Fundaro C, Genovese O, Rendeli C, Tamburrini E, Salvaggio E. Myelomeningocele in a

child with intrauterine exposure to efavirenz (vol 16, pg 299, 2002). AIDS

2002;16(10):1443-1443.

(43) Saitoh A, Hull AD, Franklin P, Spector SA. Myelomeningocele in an infant with

intrauterine exposure to efavirenz. Journal of perinatology : official journal of the California

Perinatal Association 2005 Aug;25(8):555-556.

(44) Antiretroviral Pregnancy Registry Steering Committee. The Anitretroviral Pregnancy

Registry: International Interim Report 1 January 1989 through 31 July 2009. 2009.

(45) Gerschenson M, Erhart SW, Paik CY, St Claire MC, Nagashima K, Skopets B, et al.

Fetal mitochondrial heart and skeletal muscle damage in Erythrocebus patas monkeys

exposed in utero to 3'-azido-3'-deoxythymidine. AIDS Res.Hum.Retroviruses 2000 May

1;16(7):635-644.

(46) Ewings EL, Gerschenson M, St Claire MC, Nagashima K, Skopets B, Harbaugh SW, et

al. Genotoxic and functional consequences of transplacental zidovudine exposure in fetal

monkey brain mitochondria. J.Acquir.Immune Defic.Syndr. 2000 Jun 1;24(2):100-105.

(47) Chan SS, Santos JH, Meyer JN, Mandavilli BS, Cook DL,Jr, McCash CL, et al.

Mitochondrial toxicity in hearts of CD-1 mice following perinatal exposure to AZT, 3TC, or

AZT/3TC in combination. Environ.Mol.Mutagen. 2007 Apr-May;48(3-4):190-200.

68

(48) Divi RL, Walker VE, Wade NA, Nagashima K, Seilkop SK, Adams ME, et al.

Mitochondrial damage and DNA depletion in cord blood and umbilical cord from infants

exposed in utero to Combivir. AIDS 2004 Apr 30;18(7):1013-1021.

(49) Shiramizu B, Shikuma KM, Kamemoto L, Gerschenson M, Erdem G, Pinti M, et al.

Placenta and cord blood mitochondrial DNA toxicity in HIV-infected women receiving

nucleoside reverse transcriptase inhibitors during pregnancy. J.Acquir.Immune Defic.Syndr.

2003 Apr 1;32(4):370-374.

(50) Divi RL, Leonard SL, Kuo MM, Nagashima K, Thamire C, St Claire MC, et al.

Transplacentally exposed human and monkey newborn infants show similar evidence of

nucleoside reverse transcriptase inhibitor-induced mitochondrial toxicity.

Environ.Mol.Mutagen. 2007 Apr-May;48(3-4):201-209.

(51) Lindegren ML, Rhodes P, Gordon L, Fleming P, Perinatal Safety Review Working

Group, State and Local Health Department HIV/AIDS Surveillance Programs. Drug safety

during pregnancy and in infants. Lack of mortality related to mitochondrial dysfunction

among perinatally HIV-exposed children in pediatric HIV surveillance. Ann.N.Y.Acad.Sci.

2000 Nov;918:222-235.

(52) Mofenson LM, Munderi P. Safety of antiretroviral prophylaxis of perinatal transmission

for HIV-infected pregnant women and their infants. J.Acquir.Immune Defic.Syndr. 2002 Jun

1;30(2):200-215.

(53) Money D, Maan E, Chaworth-Musters T. Mitochondrial DNA levels in pregnancy are

not decreased in ARV-treated women compared to HIV - controls. Available at:

http://www.retroconference.org/2009/Abstracts/36072.htm. Accessed 2/22/2010.

(54) Taha TE, Kumwenda N, Gibbons A, Hoover D, Lema V, Fiscus S, et al. Effect of HIV-

1 antiretroviral prophylaxis on hepatic and hematological parameters of African infants.

AIDS 2002 Apr 12;16(6):851-858.

(55) Toltzis P, Mourton T, Magnuson T. Comparative embryonic cytotoxicity of European

Collaborative Study. Exposure to antiretroviral therapy in utero or early life: the health of

uninfected children born to HIV-infected women. J.Acquir.Immune Defic.Syndr.

2003;32:380-387.

(56) Thorne C, Newell ML. Safety of agents used to prevent mother-to-child transmission of

HIV: is there any cause for concern? Drug Saf. 2007;30(3):203-213.

(57) Luzzati R, Del Bravo P, Di Perri G, Luzzani A, Concia E. Riboflavine and severe lactic

acidosis. Lancet 1999 Mar 13;353(9156):901-902.

(58) Sarner L, Fakoya A. Acute onset lactic acidosis and pancreatitis in the third trimester of

pregnancy in HIV-1 positive women taking antiretroviral medication. Sex.Transm.Infect.

2002 Feb;78(1):58-59.

69

(59) Hitti J, Frenkel LM, Stek AM, Nachman SA, Baker D, Gonzalez-Garcia A, et al.

Maternal toxicity with continuous nevirapine in pregnancy: results from PACTG 1022.

J.Acquir.Immune Defic.Syndr. 2004 Jul 1;36(3):772-776.

(60) Lyons F, Hopkins S, Kelleher B, McGeary A, Sheehan G, Geoghegan J, et al. Maternal

hepatotoxicity with nevirapine as part of combination antiretroviral therapy in pregnancy.

HIV.Med. 2006 May;7(4):255-260.

(61) Visnegarwala F, Krause KL, Musher DM. Severe diabetes associated with protease

inhibitor therapy. Ann.Intern.Med. 1997 Nov 15;127(10):947.

(62) Tang JH, Sheffield JS, Grimes J, McElwee B, Roberts SW, Laibl V, et al. Effect of

protease inhibitor therapy on glucose intolerance in pregnancy. Obstet.Gynecol. 2006

May;107(5):1115-1119.

(63) El Beitune P, Duarte G, Foss MC, Montenegro RM,Jr, Spara P, Quintana SM, et al.

Effect of antiretroviral agents on carbohydrate metabolism in HIV-1 infected pregnant

women. Diabetes Metab.Res.Rev. 2006 Jan-Feb;22(1):59-63.

(64) Burdge DR, Money DM, Forbes JC, Walmsley SL, Smaill FM, Boucher M, et al.

Canadian consensus guidelines for the care of HIV positive pregnant women: putting

recommendations into practice. CMAJ 2003 Jun 24;168(13):1683-1688.

(65) Kenny LC, Baker PN. The Etiology of Preeclampsia. In: Belfort MA, Thornton S, Saade

GR, editors. Hypertension in pregnancy New York: Marcel Dekker; 2003.

(66) Redman CW, Sacks GP, Sargent IL. Preeclampsia: an excessive maternal inflammatory

response to pregnancy. Am.J.Obstet.Gynecol. 1999 Feb;180(2 Pt 1):499-506.

(67) Dekker GA. The Immunological Aspects of Preeclampsia: Links with Current Concepts

on Etiology and Pathogenesis. In: Belfort MA, Thornton S, Saade GR, editors. Hypertension

in pregnancy New York: Marcel Dekker; 2003. p. 37-56.

(68) Redman CW. Immunology of preeclampsia. Semin.Perinatol. 1991 Jun;15(3):257-262.

(69) Roberts JM, Redman CW. Pre-eclampsia: more than pregnancy-induced hypertension.

Lancet 1993 Jun 5;341(8858):1447-1451.

(70) Strickland DM, Guzick DS, Cox K, Gant NF, Rosenfeld CR. The relationship between

abortion in the first pregnancy and development of pregnancy-induced hypertension in the

subsequent pregnancy. Am.J.Obstet.Gynecol. 1986 Jan;154(1):146-148.

(71) Seidman DS, Ever-Hadani P, Stevenson DK, Gale R. The effect of abortion on the

incidence of pre-eclampsia. Eur.J.Obstet.Gynecol.Reprod.Biol. 1989 Nov;33(2):109-114.

(72) Eras JL, Saftlas AF, Triche E, Hsu CD, Risch HA, Bracken MB. Abortion and its effect

on risk of preeclampsia and transient hypertension. Epidemiology 2000 Jan;11(1):36-43.

70

(73) Tubbergen P, Lachmeijer AM, Althuisius SM, Vlak ME, van Geijn HP, Dekker GA.

Change in paternity: a risk factor for preeclampsia in multiparous women?

J.Reprod.Immunol. 1999 Nov;45(1):81-88.

(74) Trupin LS, Simon LP, Eskenazi B. Change in paternity: a risk factor for preeclampsia in

multiparas. Epidemiology 1996 May;7(3):240-244.

(75) Li DK, Wi S. Changing paternity and the risk of preeclampsia/eclampsia in the

subsequent pregnancy. Am.J.Epidemiol. 2000 Jan 1;151(1):57-62.

(76) Marti JJ, Herrmann U. Immunogestosis: a new etiologic concept of "essential" EPH

gestosis, with special consideration of the primigravid patient; preliminary report of a clinical

study. Am.J.Obstet.Gynecol. 1977 Jul 1;128(5):489-493.

(77) Klonoff-Cohen HS, Savitz DA, Cefalo RC, McCann MF. An epidemiologic study of

contraception and preeclampsia. JAMA 1989 Dec 8;262(22):3143-3147.

(78) Einarsson JI, Sangi-Haghpeykar H, Gardner MO. Sperm exposure and development of

preeclampsia. Am.J.Obstet.Gynecol. 2003 May;188(5):1241-1243.

(79) Robillard PY, Hulsey TC, Perianin J, Janky E, Miri EH, Papiernik E. Association of

pregnancy-induced hypertension with duration of sexual cohabitation before conception.

Obstet.Gynecol.Surv. 1995;50(4):256.

(80) Robillard PY, Hulsey TC. Association of pregnancy-induced-hypertension, pre-

eclampsia, and eclampsia with duration of sexual cohabitation before conception. Lancet

1996 Mar 2;347(9001):619.

(81) Need JA, Bell B, Meffin E, Jones WR. Pre-eclampsia in pregnancies from donor

inseminations. J.Reprod.Immunol. 1983 Nov;5(6):329-338.

(82) Dekker GA, Robillard PY. Immune maladaptation in the etiology of pre-eclampsia; and

updated epidemiological perspective. In: Lyall F, Belfort MA, editors. Pre-eclampsia :

etiology and clinical practice New York: Cambridge University Press; 2007. p. 276.

(83) Salha O, Sharma V, Dada T, Nugent D, Rutherford AJ, Tomlinson AJ, et al. The

influence of donated gametes on the incidence of hypertensive disorders of pregnancy.

Hum.Reprod. 1999 Sep;14(9):2268-2273.

(84) Stratton P, Tuomala RE, Abboud R, Rodriguez E, Rich K, Pitt J, et al. Obstetric and

newborn outcomes in a cohort of HIV-infected pregnant women: a report of the women and

infants transmission study. J.Acquir.Immune Defic.Syndr.Hum.Retrovirol. 1999 Feb

1;20(2):179-186.

(85) Mawson AR. Effects of antiretroviral therapy on occurrence of pre-eclampsia. Lancet

2003 Jan 25;361(9354):347-348.

(86) de Groot M, Corporaal L, Cronjé H, Joubert G. HIV infection in critically ill obstetrical

patients. International Journal of Gynecology & Obstetrics 2003;81(1):9-16.

71

(87) Frank KA, Buchmann EJ, Schackis RC. Does human immunodeficiency virus infection

protect against preeclampsia-eclampsia? Obstetrics & Gynecology 2004;104(2):238.

(88) Bodkin C, Klopper H, Langley G. A comparison of HIV positive and negative pregnant

women at a public sector hospital in South Africa. J.Clin.Nurs. 2006;15(6):735-741.

(89) National Working Group on High Blood Pressure in Pregnancy. Report of the National

High Blood Pressure Education Program, Working Group on High Blood Pressure in

Pregnancy. Am.J.Obstet.Gynecol. 2000;183(1):00s1-0s22.

(90) American College of Obstetricians and Gynecologists Committee on Practice Bulletins-

Obstetrics. ACOG practice bulletin: diagnosis and management of pre-eclampsia and

eclampsia: Number 33. Obstet.Gynecol. 2002;99:159-167.

(91) Brown MA, Lindheimer MD, de Swiet M, Van Assche A, Moutquin JM. The

classification and diagnosis of the hypertensive disorders of pregnancy: statement from the

International Society for the Study of Hypertension in Pregnancy (ISSHP). Hypertension in

pregnancy 2001;20(1):9-14.

(92) Brown MA, Hague WM, Higgins J, Lowe S, McCowan L, Oats J, et al. The detection,

investigation and management of hypertension in pregnancy: executive summary. The

Australian New Zealand journal of obstetrics gynaecology 2000;40(2):133.

(93) Magee L, Helewa M, Moutquin J, von Dadelszen P. Diagnosis, Evaluation, and

Management of the Hypertensive Disorders of Pregnancy. Journal of obstetrics and

gynaecology Canada 2008;30(3).

(94) Kramer M, Platt R, Wen S, Joseph K, Allen A, Abrahamowicz M, et al. Fetal/Infant

Health Study Group of the Canadian Perinatal Surveillance System. A new and improved

population-based Canadian reference for birth weight for gestational age. Pediatrics

2001;108(2):E35.

(95) Kontorinis N, Dieterich DT. Toxicity of non-nucleoside analogue reverse transcriptase

inhibitors. Semin.Liver Dis. 2003 May;23(2):173-182.