Preconception Care

Question 1

What is used to diagnose sickle cell carrier status, as well as thalassemias in general?

Answer 1

Hgb electrophoresis + CBC

Question 2

Complications of uncontrolled asthma during pregnancy

Answer 2

Prematurity; preeclampsia; growth restriction; C-section; maternal morbidity/mortality

Question 3

What is the percentage chance of being sickle cell carrier in Blacks?

Answer 3

1/10

Question 4

What is the carrier frequency of cystic fibrosis in the non-Hispanic white population?

Answer 4

1/25

Question 5

What is the carrier frequency of different diseases for Ashkenazi Jews?

Answer 5

Gaucher: 1/15 - impaired fatty acid breakdown
Tay-Sachs: 1/30 - neuronal degeneration
Canavan disease: 1/55 - brain degenerates into spongy tissue with enlarged spaces
Maple syrup urine disease: 1/113 - can’t break down branched amino acids

Question 6

Valproic acid: risks to fetus

Answer 6

Neural tube defects; hydrocephalus; craniofacial malformations (facial clefts, craniosynostosis); limb defects (radial aplasia); cardiac defects; hypospadias

Question 7

Diabetes (poorly controlled): Risks to fetus

Answer 7

Structural anomalies: Neural tube defects; cardiovascular

Genitourinary defects; limb defects; caudal regression malformation (very rare)

Question 8

Name the screening tests

Answer 8

Cell-free DNA: most reliable for Trisomy 21 (99% detection rate, 0.2% false positive rate); can start at 9 wga

Others have 5% false positive rate
First trimester combined test (Nuchal translucency, PAPP-A, b-hCG): 85% detection rate
Triple screen (2nd trimester AFP, b-hCG, uE3 unconjugated estriol): 69% detection rate
Quad screen (Triple screen + inhibin A): 81% detection rate
Sequential screen (1st trimester NT and PAPP-A + quad screen): 93% detection rate
Serum integrated screen when unable to obtain NT (1st trimester PAPP-A + quad screen): 85-88%

Question 9

What is the most common form of inherited intellectual disability?

Answer 9

Fragile X - 1/3,600 males and 1/4,000 females

Question 10

What should be added for a patient on lamotrigine who wants to become pregnant?

Answer 10

Folate supplementation - decreases incidence of neural tube defects for patients on antiseizure medication

Question 11

Interpret the 100 g 3h glucose tolerance test

Answer 11

2/4 elevated values = abnormal test —> educate on diet and monitor blood glucose pre/post-prandial
Fasting < 95, 1h < 180, 2h <155, 3h <140

Question 12

Risk factors for gestational diabetes

Answer 12

Previous large baby >9 lbs; hx abnormal glucose tolerance; pre-pregnancy obesity; Native American/Hispanic ancestry

Question 13

Risks from gestational diabetes

Answer 13

Shoulder dystocia; fetal macrosomia; metabolic disturbance; preelcampsia; polyhydramnios

Question 14

When should neural tube defects be screened during pregnancy?

Answer 14

36-38 weeks via US, assessing for meningomyelocele (open spina bifida)

Question 15

What does elevated maternal serum AFP suggest?

Answer 15

Underestimation of gestational age; neural tube defect; fetal demise; multiple gestation; ventral wall defects; tumor or liver disease in patient

Question 16

Amniocentesis vs chorionic vilus sampling

Answer 16

CVS is between 10-12 wga
Amnio has highest sensitivity for Down syndrome and other chromosomal abnormalities
Amnio > cell-free DNA testing if patient has high BMI as there is risk of not enough cells

Question 17

Why should ibuprofen be stopped by 32 wga?

Answer 17

Premature closure of the ductus arteriosus

Question 18

What anticoagulation should be used during pregnancy?

Answer 18

Heparin/LMWH

Question 19

How much weight should be gained during pregnancy for the different BMIs?

Answer 19

BMI <18.5: 28-40 lbs
BMI 18.5-24.9: 25-35 lbs
BMI 25.0-29.9: 15-25 lbs
BMI >30: 11-20 lbs

Question 20

How much folate is needed for preconception planning?

Answer 20

Starting 1 month prior:
Average risk: 0.4 mg daily
High-risk: 4 mg daily

Question 21

Congenital Rubella would cause what in fetus?

Answer 21

Fetal growth restriction

Question 22

Congenital Varicella would cause what in fetus?

Answer 22

Microcephaly

Question 23

How would congenital HSV present?

Answer 23

Microcephaly

Question 24

How would congenital Syphilis present?

Answer 24

Hydrocephalus

Question 25

What puts at risk of congenital toxoplasmosis and what would you see?

Answer 25

Undercooked meat
Microcephaly, hydrocephalus, and diffuse cerebral calcifications