Some Medical Conditions in Pregnancy

Max Brinsmead PhD FRANZCOG

August 2012

Anaemia

The most common pregnancy complication worldwide

Affects 1:2 women in developing countries

Risk of maternal and fetal mortality

Also has substantial morbidity and economic sequelae

Haematocrit and Perinatal Mortality

A Definition of Anaemia:

WHO definition is Hb <110 g/L but…

Hb <100 g/L is more realistic

Needs correction for altitude…

Add 2.5 g/L for every 1000m up to 4000m

Severe when Hb is 40 – 70 g/L

Very severe when Hb is <40 g/L

Causes of Anaemia:

Nutritional deficiency of Iron and Folate

Malaria

HIV (+/- TB)

Sickle cell Disease or Thalassaemia

Hookworm infestation

Chronic renal or Hepatic disease

Often multifactorial

Losses and gains:

Non pregnant iron requirement is 2 mg/day

But this reaches 5 mg/day in 3rd trimester

Will be influenced by age, parity, pregnancy spacing and fetal number

Hookworm >1000 ova/g faeces will cause a loss of 2 mg iron/day

Folate deficiency is aggravated by malaria

B12 deficiency is rare

Investigations for Anaemia:

Blood film – look for micro or macrocytosis, reticulocytes, segmentation neutrophils, Neutrophil & Lymphocyte count

But combined deficiencies can be difficult

Malarial parasites may be intermittent or parasitised RBC’s may have been removed from circulation

Bone marrow can be useful

Malaria and Anaemia:

The picture will depend on whether the woman is immune or non immune to malaria

Splenomegaly = Hyperactive Big Spleen Syndrome

Due to an abnormal immune response to chronic malaria

Requires malarial Rx esp. Proguanil 200 mg/day for life

And Folic acid 5 mg/day

Profound Anaemia or Pre eclampsia?

Oedema can occur with hyperdynamic heart failure

Proteinuria can occur with renal hypoxia

There can be hypovolaemia with both

Profound anaemia may even present with coma

But…

Diastolic BP will be low with anaemia and high with pre eclampsia

Management of Profound Anaemia:

Admit to hospital if Ht is <0.20

Try to be as specific as possible with Rx

Iron dextran infusion can be useful• Calculate dose required• Adrenaline & hydrocortisone on standby• Follow up

Indiscriminate Fe by IM injection is not good

Parenteral folate rarely required but concomitant oral iron always required

Indications for Transfusion:

Heart failure or incipient heart failure

Ht <0.14

Miscarrying or in labour and Ht <0.18

Operation required and Ht <0.24

Other disease is present e.g. renal

Maternal Mortality and Transfusion

Transfusion Precautions:

Use packed cells and pre transfusion Lasix

May require anti malarial drugs

May require lower limb torniquets

NB The Ht will initially fall

The anaemic patient in labour:

Do everything possible to minimise blood loss

Because they may have compensated up to that point but blood loss of even 100 – 200 ml may be fatal

Monitor for signs of fetal hypoxia

Maternal oxygen can be useful

The anaemic patient who fails to respond to

treatment:

Maybe noncompliant

Has underlying renal or hepatic disease

Has chronic infection such as HIV, TB or UTI

Has concomitant malignancy

Has an advanced abdominal pregnancy

Has idiopathic hypoplastic anaemia

Thrombocytopenia and Pregnancy

Platelet count in pregnancy is normally >150,000Thrombocytopenia may be due to:– Malaria e.g. hyperactive spleen disease– HIV

• And transiently with other viral infections– Part of severe anaemia e.g. folate deficiency– Many drugs including alcohol– Fetal death in utero– Late sign in severe pre eclampsia (HELLP)– Idiopathic thrombocytopenia

IdiopathicThrombocytopenia(or ITP)

Is actually an autoimmune condition due to anti-platelet antibodies

Maternal risk of bleeding does not occur until the platelet count is <20,0000

However, there is a risk of passive transfer of antibody and fetal thrombocytopenia– That may result in intra cranial haemorrhage

This can be averted by keeping maternal count >50,000

This is done by the administration of steroids

Steroids for ITP

Inhibit anti platelet antibodies

But also coat and protect the platelets from destruction in the spleen

Check neonatal platelet levels

However, the risk of fetal bleeding is not as great as that which occurs with alloimmune ITP– When the maternal platelet count is usually normal

Thyroid Disorder

Pregnancy is a state of mild hyperthyroidism

Thyroid hormones cross the placenta poorly

But

The developing fetal brain may be dependent on some maternal thyroxin

And

Antithyroid drugs cross the placenta readily

Management of Thyroid Disorders

in Pregnancy

Hypothyroid patients require an increase in their thyroxin replacement therapy

Best option is to dose by 33% ASAP

Hyperthroid patients are best treated by PTU but “run them hot”

I131 therapy is contraindicated

Thyroid surgery is okay after toxic control

This is the hand of a 14-year primigravida whom you are seeing for the first time…

Finger Clubbing here is most likely due to…

Cyanotic congenital heart disease• Tetralogy of Fallot• Eisenmenger’s Syndrome

And you should be worried because there is a very poor prognosis• For the mother• For the fetus

Other High Risk Cardiac Conditions• Pulmonary hypertension• Severe aortic & mitral stenosis• A metal mitral valve replacement (on Warfarin)• Marfan’s syndrome with severe aortic incompetence• Peripartum cardiomyopathy

Management of Cardiac Disease

in PregnancyCardiac output increases throughout pregnancy and reaches a peak in labour

Close monitoring with multidisciplinary care is required

Low threshold for hospitalisation

Vigorous treatment of CCF

Aim for vaginal delivery

Pre term delivery may be required for severe disease

Remember thromboprophylaxis

Management of Cardiac Disease

in LabourBest done as “intensive care”

Low dose epidural good• But requires an expert anaesthetist

Assist the delivery by ventouse or forceps in a semi sitting position

Avoid all oxytocics in the third stage

And use mechanical means to control PPH

LMW heparin prophylaxis against thromboembolism

Progesterone only or T/L best afterwards

Diabetes in Pregnancy

Screening for gestational diabetes has become accepted best practice

Meticulous control of blood sugar before and during pregnancy for the best outcomes

Pre term Caesarean no longer required

But Caesarean may be the best option when fetal macrosomia is suspected