Normal Pregnancy & Antepartum Care

Question 1

Folic acid recommendations in pregnancy

Answer 1

Start folic acid supplementation at least 1 month before conception to reduce incidence of neural tube defects (NTD)

If no history of NTD — folic acid 0.4 mg

If hx of child with NTD — folic acid 4.0 mg

Question 2

What are some important components of medical history to collect during the first prenatal visit?

Answer 2

Medical history — DM, HTN

Reproductive — PTD, preeclampsia, stillbith, previous C section

Family hx — DM

Nutritional — folic acid, weight gain

Social — EtOH, illicit drugs, smoking, employment

Psychosocial issues — depression, anxiety, domestic violence

Question 3

Normal PE findings in pregnancy

Answer 3

Systolic murmurs, exaggerated splitting and S3

Palmar erythema

Spider angiomas

Linea nigra

Striae gravidarum

Chadwicks sign (blue coloration of vagina and cervix)

Question 4

Prenatal labs usually done at 1st visit

Answer 4

CBC

Type and screen

Test for rubella, syphilis (RPR), Hep B surface Ag, HIV, gonorrhea, chlamydia

Cervical cytology

Screen for DM based on risk factors (everyone is screened at 28 weeks, but screen early if there is family hx, obesity, etc.)

Urine culture

Confirm pregnancy and viability, estimate gestational age and due date

Question 5

Naegels rule for estimating due date

Answer 5

LMP minus 3 months + 7 days = expected date of delivery

[note: only useful in pts with regular 28 day cycles]

Question 6

Due date can be estimated using date of LMP, PE of uterus size, or ultrasound exam. How does US help determine due date?

Answer 6

Crown Rump Length (CRL) between 6-11 weeks can determine due date within 7 days

At 12-20 weeks measuring femur length, biparietal diameter and abdominal circumference can determine due date w/i 10 days

In third trimester, due date can be off up to 3 weeks

Question 7

What pt populations require genetic counseling in pregnancy?

Answer 7

Advanced maternal age (35+)

Previous child/family hx of birth defects or known genetic disorder

Previous child with undiagnosed mental retardation

Previous baby who died in neonatal period

Multiple fetal losses

Abnormal serum marker screening

Exposure to teratogens

Abnormal US findings

Question 8

Most common autosomal recessive gene carried in North American whites, frequency of 1/25

Answer 8

Cystic fibrosis

[screening is offered to all pregnant women, people with family hx, partners of known CF carriers, US findings of echogenic bowel, sperm donors]

Question 9

Duchenne muscular dystrophy and fragile X syndrome are examples of _______ inherited disorders

Answer 9

X-linked

Question 10

Most common form of inherited mental retardation and second most common form of mental retardation after trisomy 21

Answer 10

Fragile X syndrome

Question 11

Multiple tests are available for maternal screening for fetal aneuploidy. What screening tests may be done in the first trimester?

Answer 11

First trimester screening includes:

Maternal age

Fetal nuchal translucency (NT) thickness (echo free area at back of fetal neck between 10-14 wks)

Maternal serum b-hCG

Pregnancy associated plasma protein-A (PAPP-A)

Question 12

An elevated beta-hCG and low PAPP-A is associated with ______

Answer 12

Downs syndrome

Question 13

Multiple tests are available for maternal screening for fetal aneuploidy. What screening tests may be done in the second trimester?

Answer 13

Triple screen done between 16-20 wks: Beta-hCG, estriol, and maternal serum alpha fetoprotein (AFP) biomarkers

Or can do quadruple screen: beta-hCG, estriol, AFP, and inhibin A

Question 14

Noninvasive prenatal test performed at 9-10 weeks with very high detection rates for trisomies and other sex chromosome abnormalities

Answer 14

Cell-free fetal DNA [if positive, proceed with invasive diagnostic testing like amniocentesis or CVS]

Question 15

Second trimester testing may include amniocentesis and/or chorionic villi sampling — when are these tests usually performed (at how many weeks?)

Answer 15

Amniocentesis — 16-20 wks

CVS — 11 wks

Question 16

Teratogenic drug well known for causing phocomelia

Answer 16

Thalidomide

Question 17

The most vulnerable stage to teratogens is from day ____-____ post-conception during which time organogenesis is occurring

Answer 17

17-56

Question 18

Most common teratogen to which a fetus is exposed

Answer 18

Alcohol

Question 19

Antianxiety and antineoplastic teratogenic agents

Answer 19

Antianxiety: Meprobamate, chlordiazeopoxide (fluoxetine is drug of choice in pregnancy)

Antineoplastic: MTX, aminopterin, busulfan, chlorambucil, cyclophosphamide

Question 20

Anticoagulants and anticonvulstant teratogenic agents

Answer 20

Anticoagulants: coumadin (heparin is drug of choice in pregnancy)

Anticonvulsants: diphenylhydantoin — causes fetal hydantoin syndrome (FHS), valproic acid, carbamazepine, phenobarbital

Question 21

Effect of radiation on developing fetus

Answer 21

Effects are dose dependent

Critical period is between 2-6 weeks post-conception

If exposure is before 2 weeks, there is lethal effect or no effect at all

Rule of thumb: less than 5 rads of exposure = no risk

Question 22

Management of N/V of pregnancy

Answer 22

Eat small frequent meals, avoid greasy/fried food, room temp sodas and saltine crackers, accupuncture

Medications: antihistamines, vitamin B6, antiemetics (phenergan, zofran)

Question 23

Heartburn affects 2/3 of pregnancies d/t relaxation of esophageal sphincter by progesterone. How is this managed?

Answer 23

Do not lie down immediately after meals, elevate head of the bed, eat small frequent meals, antacids, H2 blockers like pepcid or zantac

Question 24

Frequency of prenatal office visits

Answer 24

Every 4 weeks until 28 weeks

Every 2 weeks from 28-36 weeks

Weekly until delivery

Question 25

What occurs at routine prenatal office visits?

Answer 25

Blood pressure

Weight

Urine protein

Measurement of uterine size

Fetal heart rate

Address fetal movement/kick counts

Education on preterm and term labor, rupture of membranes, preeclampsia, and address any other identified potential complications

Discuss lifestyle

Question 26

What special tests occur at 20 weeks, 28 weeks, and 35 weeks during routine pregnancy visits?

Answer 26

20 weeks: obtain fetal survey ultrasound

28 weeks: screen for gestational diabetes and repeat hemoglobin and hematocrit, Rhogam injectioin to Rh negative pts, Tdap given between 27-36 weeks

35 weeks: screen for group B strep carrier with vaginal culture — treat in labor if positive

Question 27

Methods for assessing fetal well being

Answer 27

Kick counting — monitor fetal movement for at least 10 movements in 2 hours (movement begins at ~28 weeks)

Nonstress test (NST) — reactive (normal) result is 2 accelerations of at least 15 beats above baseline lasting at least 15 seconds during 20 minutes of monitoring (if nonreactive, further eval with contraction stress test or biophysical profile)

Contraction stress test (CST) — give oxytocin to establish at least 3 contractions in a 10 minute period. If late decelerations are noted with majority of contractions, the test is positive and delivery is warranted

Question 28

5 Components of biophysical profile

Answer 28

1. Nonstress test (NST) [reactive]
2. Fetal breathing movements [1+ episode of rhythmic fetal breathing movements of 30 sec or more w/i 30 mins]
3. Fetal movement [3+ discrete movements w/i 30 mins]
4. Fetal tone [1+ episode of extremity extension with return to flexion, or opening/closing of hand w/i 30 mins]
5. Amniotic fluid volume [pocket of fluid measures at least 2 cm in 2 perpendicular planes]

Total score of 8-10 is reassuring, score of 6 is equivocal and delivery is warranted if pt at term gestation, score of 4 or less is nonreassuring and delivery may be considered