ob nursing: fetal conception/development; pregnancy

OB Nursing: Fetal conception/development; Pregnancy

Review Questions: Conception Case Study (word doc and end of ppt), Saunders: p. 303 242-251; 322 262-276, 340 277-290; Lippincott: p. 36 1-115, p. 67 1-97

Topics covered include: Changes during pregnancy, nutrition/weight gain, antenatal testing, prenatal

care, bleeding during pregnancy

Maternal Morbidity and Mortality:

o US ranks 49th in list of rates of industrialized nations

o US ranks 30/31 for infant mortality

o Causes of maternal morbidity and mortality:

HTN

Emboli

Infx

Hemorrage

o Neonatal/fetal morbidity and mortality:

Low birth weight

Congenital anomalies

Consequences of maternal disease

Prematurity

Selected Anatomy and Physiology Review:

o Caldwell-Molloy pelvic types:



Gynecoid is ideal, others may present difficulties

o Android: narrower midpelvis complicates travel

o Antrhopoid: narrower inlet

o Platypelloid: wider outlet

Ischial spines: toughest part of birth passage

Pubic crest can (and does) break

Hormones:

o Estrogens:

Estradiol: available only during reproductive years

Estriol: available only during pregnancy

Estrone: Estrogen of menopause

o Progesterone: THE PREGNANCY HORMONE

o Prostaglandins

PGe: vasodilation, smooth muscle relaxant

PGf: vasoconstriction, smooth muscle contraction

The Female Reproductive Cycle

o Highlights:

Cycle is comprised of (3) Main Phases: Follicular phase, Ovulation, and

Luteal Phase

Because luteal phase is more regular (approx. 14 days), if we know length of

cycle and it’s regularity we can predict ovulation.

By default this makes the follicular phase the more variable part of

the cycle

During the follicular phase, estrogen is the predominant hormone and a

surge of Luteinizing Hormone (LH) causes release of the ovum (egg) from

the follicle. Following this, the follicle forms into the Corpus Luteum (CL) to

support pregnancy. Progesterone becomes dominant hormone.

During this time, the uterine tissue is building up and preparing for

implantation of the fertilized embryo (known as the secretory phase).

If there is no sustained pregnancy, the lining is shed through the

menstrual phase, occurring at the end of the cycle (Important to

know LAST KNOWN MENSTURAL PERIOD (the first day of bleeding)

Can be used in determining cycle length, potential pregnancy)



Development of Pregnancy

o Terminology:

Gestational age: Includes length of pregnancy + 2 Additional Weeks (1 Week

for LMP, and preceding week)*ASSUMES A REGULAR 28 DAY CYCLE*

Pregnancy typically lasts 280 gestational days:

o 40 weeks

o 10 lunar months

o 9ish calendar months

Fertilization: union of ovum and sperm in the ampulla of the fallopian tube

Cellular Multiplication:

Zygote (4 cell mass) differentiates into Morula (Day 3)

Morula further differentiates into Blastocyst and Trophoblast (by

Day 5)

o Blastocyst: inner cell mass which will become embryo,

amnion, & yolk sac

o Trophoblast: outer layer which becomes chorion and

placenta

Trophoblast IMPLANTS into endometrium between days 6-10

o Formation of Chorionic villi serves 2 functions:

Maintains estrogen/progesterone

Inhibits ovarian and menstrual cycles

Cellular Differentiation:

Differentiation of germ layers: ectoderm, endoderm, mesoderm

o Ectoderm: Epidermis, hair, teeth, facial features, CNS

o Endoderm: Dermis, muscles, bones, kidneys, ears, lymph,

CV, spleen

o Mesoderm: organs

Embryonic membranes: chorion, amnion

Amniotic fluid

Yolk sacprimitive RBCs

Umbilical cord



First two weeks following conception= embryo is most likely to be damaged, most succepitble to

teratogens

Fetal developmental milestones:

o 28 Days p conception: Heart beat

o 4-6 weeks: Male differentiation BEGINS (not necessarily determinable)

o 8-10 wks: all organs formed

o 16 wks: Fetal respiration

o 23 wks: Youngest preterm survivor

Review of fetal circulation:

o Teratogens:

ETOH: no safe allowable level established

Caffeine: hard to determine effects, restrict until 2nd/3rd trimester and then limit

intake

Drug classifications:

Category A: OK

B: No risk in anaimals

C: questionable risk



D: Evidence of risk

X: definite risk (i.e. ASPIRIN! BECAUSE IT CLOSES FETAL CIRCULATORY

DUCTS)

Maternal changes during pregnancy

o Familial changes:

Role crisis, perceived body image, financial concerns

Hensley’s rule: 1) Include the partner 2) Don’t assume gender of partner

o Psychosocial adaptations:

1st Trimester: Surprise, ambivalence, focus on discomforts

2nd: Accept growing fetus, introversion

3rd: Preparation for birth, focus on physical discomforts, preparation of maternal role

o Partner couvade: Unintentional taking on of symptoms by partner

o Physical changes:

Signs of pregnancy (with differentials):

Presumptive:

o Nausea (upset stomach, flu, food poisoning)

o Fatigue (sleep deprivation)

o Breast tenderness (fluctuates with cycle)

o Vomiting (food poisoning, migraines)

o Weight gain (sedentary lifestyle, diet)

o Urinary frequency (UTI, cystitis)

o Quickening (fluttering sensation: gas, ovulation)

Can be expected at 18-20

weeks

o Ammenorrhea (low body weight, irregular cycle, contraceptive

use)

o Abdominal striae (weight/muscle gain)

Skin alterations attributed

to estrogen

Probable:

o Uterine souffle (uterine myomas)

soft bowing sound in sound

with maternal pulse due to

increased vascularization

o Chadwick’s sign (intense intercourse)

“blue” vagina d/t incr

vascularization

o Ballotment (ghost pregnancy, ascities, polyps/fibroids)

Passive fetal movements

elicited by palpating cervix

o Goodell’s sign (hormonal contraception, intense intercourse)



Softening of cervix

o Progressive enlargement of abdomen (obesity, ascities, pelvic

tumors)

o Palpation of fetal outline (uterine myoma)

o Braxton-Hick’s contractions (soft myomas)

o Darkened areola (sun, hormonal contraception)

o Positive pregnancy test (false positive, inpropper

use/interpretation, proteinuria)

o Linea negra (hormonal stimulation)

Positive

o Fetal heartbeat per Doppler

o Fetal heartbeat per fetoscope

o Fetal movement per trained provider

o Visualization of fetus on US

Enlarging uterus has effects on:

Lungs, diaphragm: displacementdecr tidal volumeshortness of breath

Intestines: again displacement alters function

Bladder

Spine curvature

o By 20 weeks, women experience an exaggerated lordosis, can

be corrected by alternating legs on a stool

o Altered center of gravity: PROBLEMATIC b/c more prone to falls

Round uterine ligaments

o Late into pregnancy, sudden movement can pull on ligmanets

causing “stabbing pain” Need to warn and teach to splint to

decr pain

HEENT

Bleeding gums, nose bleeds, sensitivity to tastes/smells

Skin/Hair

Linea nigra, striae , acne vulagris, darkening areola, increased hair, palmar

erythema

Melasma (Cholasma): appearance of gray/brown patches on face

Spider angiomas

Warn patients about cocoa butter and caffeine

Breasts

Glandular hypertrophy, tenderness, nipple sensitivity, vein prominence,

colostrum

Resp

Respiratory alkalosis (breathing off CO2 through rapid exhalation)

Incr respiratory rate

20% increased oxygen consumption

GI:

Decr GI motility and emptying



N/V

Incr risk for gallstones

Heartburn: progesterone “softens” cardiac sphincter

Hemmoroids

Elevated, benign alkaline phosphate

Renal:

Incr renal blood flow

Renal stasis in pelvicies (risk for UTI)

Incr GFR: So increased, it may cause filtrate to slip through showing benign

proteinuria or glycosuria

CV

Increase in stroke volume, heart rate, cardiac output, and blood volume

(HUGE)

o Incr in HR by 10-15 beats

Decrease in blood pressure (systemic vasodilation)

Systolic murmur d/t fluid overload

Incr in clotting factors

Hematologic

Physiologic anemia of pregnancy: dilutional anemia due to incr blood

volume

o Monitor, treat at 11

Vena Cava Syndrome

Implications for prenatal/labor

Decr venous return when laying supine

Complaints of discomforts in pregnancy are ALWAYS treated as serious until proven benign

o ALWAYS serious until proven benign

o Infections:

S/sx: itching, increase in purulent (white) d/c, smell or not, dysuria

Problematic: Incr risk for preterm labor

o PROM (Premature Rupture of membranes)

Miconium (greenish tinged fluid): aspiration risk for fetus, potential sign of fetal stress

Mucus plug (clear, snot-like)

o Pre-eclampsia (Wil be discussed later)

S/sx: sudden onset of swelling, HA, “floaters”

o Hyper-emesis gravidum

Unknown cause (potentially hCG)

Concern if last PO was over 12 hours

o Pre-term labor

Sometimes sneaky “back labor”



At-risk pregnancies

o Hypertensive disorders of pregnancy

Chronic Hypertension

Pre-pregnancy BP > 140/90

OR

BP is > 140/90 before 20 weeks gestation without proteinuria

TX: >160/105 with labetalol, nifedipine, methyldopa

o Goal is 120-160/80-105

o More frequent Prenatal visits

o IOL recommended at 38 weeks

Need to be concerned with aggressive treatment, if decrease supply to

placenta can late decelerations

Preeclampsia

HTN that occurs AFTER 20 WEEKS accompanied by:

o Proteinuria OR

>300 mg/dL on 24 hr urine,

urine dipstick of at least 1+

o New onset of 1 severe feature

Severe HTN (SBP >190, DBP

>110)

Thrombocytopenia (plt cnt

<100,000)

Renal insufficiency

Impaired liver function

(doubled LFTs/ persistent

RUQ/epigastric pain)

Pulmonary edema

Cerebral/visual symptoms

Preeclampsia without severe features

Preeclampsia with severe features

Patho: unknown attributed to placental blood supply leading to maternal

vasospam and decreased organ perfusion

Tx: Delivery of fetus and removal of placenta

o If <37 wks WITHOUT severe features: Expectant mgmt. until

planned delivery at 37 weeks

o If >37 weeks WITHOUT severe features: Delivery

o If <34 weeks WITH severe features: Corticosteroids and Mag

sulfate-48 hrs later delivery

o If suspected abruption, eclamptic seizure, or severe IUGR:

DELVERY

Goals:

o Prevention of sz, stroke, hematologic/renal/heaptic disease

o Birth of neonate as close to term as possible



Assessment:

o During labor: BPs q 15 min x4, lung sounds, lab tests q6 to catch

HELLP [hemolysis, elevated liver enzymes, low platelet count],

DTR/clonus (pre-eclampsia or MAG toxicity), fundal checks, UCs

o HA, visual disturbances, epigastric pain

o Safety checks, room checks, continuous EFM

o Hourly assessment with Mag:

Make sure Dtr still present

(even if decreased)

RESP: >12/min

UO: >30 mL/hr

Serum level: 4-7 mEq/mL

Effects on contraction,

immediate postpartum, CLE

administration

Complications:

o Eclampsia: seizure in woman with preeclampsia which can’t be

attributed to another cause

Superimposed preeclampsia

Onset of severe feature or proteinuria in pt with chronic htn

Gestational Hypertension

o TORCH Viral Infections:

Toxoplasmosis

Blindness, deafeness, retardation in fetus

Other: varicella, parovirus (“fifth’s disease), syphilis, listeria, coxsackie

Varicella: maternal death d/t pneumonia, limb hypoplasia, contractures,

CNS involvement

Fifth’s: fetal death, fetal hydrops

L&C: miscarriage, fetal death, encephalitis

Rubella

Cataracts, sensorineural deafness, congenital heart defects, mental

retardation, cerebral palsy

CMV

Fetal death, SGA, micro/hydrocephaly, cerebral palsy, mental retardation

HSV

o Other infections:

STI’s

Chlamydia: ophthalmic neonatorum, PNA

Tuberculosis:

Active TB: no direct contact with newborn until non-nfectious

Inactive: May breastfeed, treatment delayed until post-partum



GBS discussed in L&D

o Diabetes:

In early pregnancy, placenta stimulates insulin production

In later pregnancy, pregnancy hormones lead to insulin resistance allowing for greater

access to fetus

Different diagnoses:

TIDM

TIIDM

A1GDM (Diet controlled gestational diabetes)

A2GDM (Medication required gestational diabetes)

Screening:

Pre-exisiting are not screened

Low risk: screened with 1 hr gtt

High risk: early 1 hr gtt before universal screen at 24-28 weeks

Normal value is <135 mg/dL

o If 135-180 proceed to 3hr gtt

Antental/Prenatal Care

o Pre-conception health goals:

Normal BMI, reg daily exercise, dental work up, varicella/MMR vaccines (live

vaccines), GYN care up to date, tracking of menses, prenatal vitamins (Folic acid 6 wks

prior to pregnancy, absorption finished at 10 wks)

o At first prenatal visit:

Establish/accurately date pregnancy

Evaluate risk factors

Support for discomforts and anticipatory guidance

o Establishing due date:

40 weeks from LMP

Neagle’s Rule: LMP + 1 yr – 3 months + 7 days

Ultrasound: accuracy in first trimester is within 5-7 days (keep EDD and suspect

developmental delays)

o Rh Status:

Rhogam: give 28 weeks, within 72 hrs of delivery

o Gs and Ps GxPxTPAL

G= Gravidity: ALL PREGNANCIES, regardless of outcome

P=Parity: Number of births after 20 weeks born dead or alive

o Uterine emptying: only emptied once with twins/triplets/etc

T: Term (how many babies delivered at later than 37 wks)

P: Pre-term: babies from 20 to 37-38 weeks

A: Abortions: spontaneous or therapeutic; LESS THAN 20 WEEKS

L: Living children



o Anticipatory Guidance: Weight Gain

IOM Guidelines based on Pre-pregnancy BMI

Underweight (<18.5): Gain 28-40 lbs

Normal (18.5-24.9): Gain 25-35 lbs

Overweight (25-29.9): Gain 15-25 lbs

Obese: Gain 11-20 lbs

Inadequate weight gain increases likelihood of low birth weight baby

Obesity during pregnancy increases risk of:

NTDs, HTN, pre-gestational diabetes, gestational diabetes, sleep apnea

Primary/repeat c/s, medical inducation/augmentation, prolonged first

stage, excessive blood loss, macrosomia

Wound infection, urinary incontinence, postpartum hemorrhage, retained

weight, failure to initiate breastfeeding

For a woman with a normal BMI:

0.5-3 lbs gain during total first trimester followed by 1 pound/wk

o Anticipatory Guidance: Antenatal Testing

Screening: Determines RISK

Quad Screen

o Screens for Trisomy 18 and 21

o 15-25 weeks

Sequential Screen

o Screens for Trisomy 13, 18, 21; cardiac/neural tube defects

o New standard screen

o 1st draw at 10-13 weeks; 2nd draw at 15-21 weeks

Cell-Free DNA

o Screens Trisomy 13, 18, 21

o After 10 wks measures fetal DNA in maternal blood

MaterniT21

o Screens for Trisomy 13,16,18,20,21; chromosome aneuploidies

and microdeletions

Carrier Screening

ROS Sonogram

o 2nd/3rd trimester

o Identifies:

Fetal presentation/number

Amniotic fluid index

Placental location

Presence of cardiac activity

Fetal biometry

Anatomy

Diagnostic

Chorionic villus sampling

o 10-12 weeks used for genetic, metabolic, DNA abnormalities



o Transabdominal/transcervical

o Does not detect neural tube defects

o Risks: SAB, fetal loss, fetal limb defects, bleeding, infx, leaking

amniotic fluid

Amniocentesis

o 15-18 wks

o Needle guided aspiration of amniotic fluid

o Less risk than CVS

Percutaneous umbilical cord blood sampling

o Obtain fetal blood from base of umbilical cord

o Dx: Hemophilia, hemolytic disorders, fetal infections,

chromosomal abnormalities, fetal hydrops, fetal H&H

ob nursing: fetal conception/development; pregnancy

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