OB/GYN BOARD PREP EXAM HIGH-YIELD REAL QUESTIONS + DETAILED
ANSWERS - LATEST VERSION - TOP RATED 2026/2027
Q1. What is Naegele's rule for calculating the estimated due date (EDD)?
ANSWER Add 7 days to the first day of the last menstrual period (LMP), then
subtract 3 months (or add 9 months). Example: LMP Jan 1 → EDD Oct 8.
Q2. What are the components of the first trimester screen?
ANSWER Nuchal translucency (NT) ultrasound + maternal serum PAPP-A and
free β-hCG, performed at 11–13+6 weeks gestation.
Q3. What is the normal range for nuchal translucency (NT) measurement?
ANSWER Less than 3.0 mm is considered normal. NT ≥3.0 mm is associated
with increased risk of chromosomal abnormalities (e.g., trisomy 21, 18, 13) and
cardiac defects.
Q4. What fetal movements are expected and when does quickening occur?
ANSWER Quickening (first perception of fetal movement) occurs at ~18–20
weeks in primigravidas and ~16–18 weeks in multigravidas. After 28 weeks,
patients should feel ≥10 movements in 2 hours.
Q5. Define gravida and para.
ANSWER Gravida = total number of pregnancies (including current). Para =
outcomes of pregnancies ≥20 weeks. TPAL notation: Term, Preterm, Abortions
(SAB/TAB), Living children.
Q6. What are the physiological changes in blood pressure during
pregnancy?
ANSWER BP decreases in the first and second trimesters (due to reduced SVR
from progesterone-mediated vasodilation), reaching a nadir around 20–24
weeks, then returns to baseline by term.
,Q7. What is the normal weight gain recommendation in pregnancy for a
normal BMI woman?
ANSWER 25–35 lbs (11.5–16 kg) for a woman with a normal BMI (18.5–24.9).
Underweight: 28–40 lbs; Overweight: 15–25 lbs; Obese: 11–20 lbs.
Q8. When is prenatal folic acid supplementation recommended and at what
dose?
ANSWER All women of reproductive age should take 0.4–0.8 mg/day. Women
with prior NTD-affected pregnancy should take 4 mg/day, starting at least 1
month before conception and continuing through the first trimester.
Q9. What vaccines are recommended during pregnancy?
ANSWER Tdap (27–36 weeks, every pregnancy), influenza (inactivated, any
trimester), and COVID-19. MMR, varicella, and live vaccines are contraindicated
in pregnancy.
Q10. What is the significance of fundal height measurement?
ANSWER Fundal height (in cm) approximately equals gestational age in weeks
between 20–36 weeks. Discrepancy of >2–3 cm warrants ultrasound evaluation
for IUGR, macrosomia, or amniotic fluid abnormalities.
PRENATAL TESTING
Q11. What does a quad screen test for and when is it performed?
ANSWER Performed at 15–20 weeks. Tests AFP, hCG, estriol, and inhibin A.
Abnormal patterns suggest trisomy 21, trisomy 18, or open neural tube defects.
Q12. What is cell-free DNA (cfDNA) screening?
ANSWER Non-invasive prenatal testing (NIPT) analyzing fetal DNA fragments
in maternal blood. Screens for trisomy 21, 18, 13, sex chromosome
abnormalities, and microdeletions. Performed from 10 weeks onward.
Q13. What are indications for amniocentesis?
, ANSWER Advanced maternal age ≥35, abnormal screening (NIPT, quad
screen), abnormal ultrasound findings, prior child with chromosomal abnormality,
balanced translocation in parent, parental anxiety.
Q14. What is the risk of fetal loss with amniocentesis vs. CVS?
ANSWER Amniocentesis (15–20 weeks): ~0.1–0.3% procedure-related loss.
CVS (10–13 weeks): ~0.5–1% loss. CVS allows earlier diagnosis but has slightly
higher risk.
Q15. What is a biophysical profile (BPP) and what is a normal score?
ANSWER Ultrasound assessment of: fetal breathing movements, gross body
movement, tone, and amniotic fluid index (AFI), plus NST. Each component
scores 0 or 2. Score ≥8/10 is reassuring; ≤4/10 is concerning.
Q16. What is the difference between a reactive and non-reactive NST?
ANSWER Reactive NST: ≥2 accelerations of ≥15 bpm above baseline lasting
≥15 seconds in 20 minutes (reassuring). Non-reactive NST: fails to meet criteria;
requires further evaluation (BPP, CST).
Q17. When is GBS screening performed and what is the management?
ANSWER Vaginal-rectal culture at 36–37 weeks. GBS-positive patients receive
intrapartum penicillin G (or ampicillin, or clindamycin if allergic and susceptible)
to prevent neonatal early-onset GBS disease.
Q18. What is the 1-hour glucose challenge test (GCT) cutoff and what does
a positive result mean?
ANSWER 50g oral glucose load; 1-hour value ≥140 mg/dL (some use 130
mg/dL) is a positive screen and requires a 3-hour 100g OGTT for diagnosis of
GDM.
Q19. What are the Carpenter-Coustan criteria for diagnosing GDM on 3-
hour OGTT?
ANSWER Two or more values must meet/exceed: Fasting ≥95 mg/dL, 1h ≥180,
2h ≥155, 3h ≥140 mg/dL. One abnormal value = impaired glucose tolerance
(treat some centers).
, Q20. What is the purpose of Doppler umbilical artery velocimetry?
ANSWER Assesses placental resistance. Absent or reversed end-diastolic flow
(AREDF) is associated with severe IUGR, placental insufficiency, and
significantly increased perinatal morbidity/mortality.
OBSTETRIC COMPLICATIONS
Q21. Define preeclampsia and its diagnostic criteria.
ANSWER New-onset hypertension (≥140/90 mmHg on two occasions ≥4h
apart) after 20 weeks + proteinuria (≥300mg/24h or PCR ≥0.3) OR severe
features (BP ≥160/110, thrombocytopenia, renal insufficiency, impaired liver
function, pulmonary edema, new headache, visual symptoms).
Q22. What is HELLP syndrome?
ANSWER Hemolysis, Elevated Liver enzymes, Low Platelets. A severe variant
of preeclampsia. Labs: LDH >600, AST/ALT >70, platelets <100,000. Associated
with DIC, hepatic rupture, maternal/fetal death.
Q23. What is the definitive treatment for preeclampsia?
ANSWER Delivery. Magnesium sulfate is used for seizure prophylaxis.
Antihypertensives (labetalol, hydralazine, nifedipine) control acute severe
hypertension. Timing of delivery depends on gestational age and severity.
Q24. What are the magnesium sulfate dosing regimens for eclampsia?
ANSWER Loading dose: 4–6 g IV over 15–20 minutes. Maintenance: 1–2
g/hour IV. Therapeutic level: 4–7 mEq/L. Toxicity: loss of DTRs (>7), respiratory
depression (>10), cardiac arrest (>15). Antidote: calcium gluconate 1g IV.
Q25. What is placenta previa and how does it typically present?
ANSWER Placenta covering the internal cervical os. Presents with painless,
bright red vaginal bleeding in the second/third trimester. Diagnosed by
ultrasound. Vaginal exam is contraindicated. Delivery by cesarean section.
Q26. What is placental abruption and how does it present?
ANSWERS - LATEST VERSION - TOP RATED 2026/2027
Q1. What is Naegele's rule for calculating the estimated due date (EDD)?
ANSWER Add 7 days to the first day of the last menstrual period (LMP), then
subtract 3 months (or add 9 months). Example: LMP Jan 1 → EDD Oct 8.
Q2. What are the components of the first trimester screen?
ANSWER Nuchal translucency (NT) ultrasound + maternal serum PAPP-A and
free β-hCG, performed at 11–13+6 weeks gestation.
Q3. What is the normal range for nuchal translucency (NT) measurement?
ANSWER Less than 3.0 mm is considered normal. NT ≥3.0 mm is associated
with increased risk of chromosomal abnormalities (e.g., trisomy 21, 18, 13) and
cardiac defects.
Q4. What fetal movements are expected and when does quickening occur?
ANSWER Quickening (first perception of fetal movement) occurs at ~18–20
weeks in primigravidas and ~16–18 weeks in multigravidas. After 28 weeks,
patients should feel ≥10 movements in 2 hours.
Q5. Define gravida and para.
ANSWER Gravida = total number of pregnancies (including current). Para =
outcomes of pregnancies ≥20 weeks. TPAL notation: Term, Preterm, Abortions
(SAB/TAB), Living children.
Q6. What are the physiological changes in blood pressure during
pregnancy?
ANSWER BP decreases in the first and second trimesters (due to reduced SVR
from progesterone-mediated vasodilation), reaching a nadir around 20–24
weeks, then returns to baseline by term.
,Q7. What is the normal weight gain recommendation in pregnancy for a
normal BMI woman?
ANSWER 25–35 lbs (11.5–16 kg) for a woman with a normal BMI (18.5–24.9).
Underweight: 28–40 lbs; Overweight: 15–25 lbs; Obese: 11–20 lbs.
Q8. When is prenatal folic acid supplementation recommended and at what
dose?
ANSWER All women of reproductive age should take 0.4–0.8 mg/day. Women
with prior NTD-affected pregnancy should take 4 mg/day, starting at least 1
month before conception and continuing through the first trimester.
Q9. What vaccines are recommended during pregnancy?
ANSWER Tdap (27–36 weeks, every pregnancy), influenza (inactivated, any
trimester), and COVID-19. MMR, varicella, and live vaccines are contraindicated
in pregnancy.
Q10. What is the significance of fundal height measurement?
ANSWER Fundal height (in cm) approximately equals gestational age in weeks
between 20–36 weeks. Discrepancy of >2–3 cm warrants ultrasound evaluation
for IUGR, macrosomia, or amniotic fluid abnormalities.
PRENATAL TESTING
Q11. What does a quad screen test for and when is it performed?
ANSWER Performed at 15–20 weeks. Tests AFP, hCG, estriol, and inhibin A.
Abnormal patterns suggest trisomy 21, trisomy 18, or open neural tube defects.
Q12. What is cell-free DNA (cfDNA) screening?
ANSWER Non-invasive prenatal testing (NIPT) analyzing fetal DNA fragments
in maternal blood. Screens for trisomy 21, 18, 13, sex chromosome
abnormalities, and microdeletions. Performed from 10 weeks onward.
Q13. What are indications for amniocentesis?
, ANSWER Advanced maternal age ≥35, abnormal screening (NIPT, quad
screen), abnormal ultrasound findings, prior child with chromosomal abnormality,
balanced translocation in parent, parental anxiety.
Q14. What is the risk of fetal loss with amniocentesis vs. CVS?
ANSWER Amniocentesis (15–20 weeks): ~0.1–0.3% procedure-related loss.
CVS (10–13 weeks): ~0.5–1% loss. CVS allows earlier diagnosis but has slightly
higher risk.
Q15. What is a biophysical profile (BPP) and what is a normal score?
ANSWER Ultrasound assessment of: fetal breathing movements, gross body
movement, tone, and amniotic fluid index (AFI), plus NST. Each component
scores 0 or 2. Score ≥8/10 is reassuring; ≤4/10 is concerning.
Q16. What is the difference between a reactive and non-reactive NST?
ANSWER Reactive NST: ≥2 accelerations of ≥15 bpm above baseline lasting
≥15 seconds in 20 minutes (reassuring). Non-reactive NST: fails to meet criteria;
requires further evaluation (BPP, CST).
Q17. When is GBS screening performed and what is the management?
ANSWER Vaginal-rectal culture at 36–37 weeks. GBS-positive patients receive
intrapartum penicillin G (or ampicillin, or clindamycin if allergic and susceptible)
to prevent neonatal early-onset GBS disease.
Q18. What is the 1-hour glucose challenge test (GCT) cutoff and what does
a positive result mean?
ANSWER 50g oral glucose load; 1-hour value ≥140 mg/dL (some use 130
mg/dL) is a positive screen and requires a 3-hour 100g OGTT for diagnosis of
GDM.
Q19. What are the Carpenter-Coustan criteria for diagnosing GDM on 3-
hour OGTT?
ANSWER Two or more values must meet/exceed: Fasting ≥95 mg/dL, 1h ≥180,
2h ≥155, 3h ≥140 mg/dL. One abnormal value = impaired glucose tolerance
(treat some centers).
, Q20. What is the purpose of Doppler umbilical artery velocimetry?
ANSWER Assesses placental resistance. Absent or reversed end-diastolic flow
(AREDF) is associated with severe IUGR, placental insufficiency, and
significantly increased perinatal morbidity/mortality.
OBSTETRIC COMPLICATIONS
Q21. Define preeclampsia and its diagnostic criteria.
ANSWER New-onset hypertension (≥140/90 mmHg on two occasions ≥4h
apart) after 20 weeks + proteinuria (≥300mg/24h or PCR ≥0.3) OR severe
features (BP ≥160/110, thrombocytopenia, renal insufficiency, impaired liver
function, pulmonary edema, new headache, visual symptoms).
Q22. What is HELLP syndrome?
ANSWER Hemolysis, Elevated Liver enzymes, Low Platelets. A severe variant
of preeclampsia. Labs: LDH >600, AST/ALT >70, platelets <100,000. Associated
with DIC, hepatic rupture, maternal/fetal death.
Q23. What is the definitive treatment for preeclampsia?
ANSWER Delivery. Magnesium sulfate is used for seizure prophylaxis.
Antihypertensives (labetalol, hydralazine, nifedipine) control acute severe
hypertension. Timing of delivery depends on gestational age and severity.
Q24. What are the magnesium sulfate dosing regimens for eclampsia?
ANSWER Loading dose: 4–6 g IV over 15–20 minutes. Maintenance: 1–2
g/hour IV. Therapeutic level: 4–7 mEq/L. Toxicity: loss of DTRs (>7), respiratory
depression (>10), cardiac arrest (>15). Antidote: calcium gluconate 1g IV.
Q25. What is placenta previa and how does it typically present?
ANSWER Placenta covering the internal cervical os. Presents with painless,
bright red vaginal bleeding in the second/third trimester. Diagnosed by
ultrasound. Vaginal exam is contraindicated. Delivery by cesarean section.
Q26. What is placental abruption and how does it present?
