Maternal-Fetal Medicine Practice Questions

Q: A 25-year-old pregnant female at 30 weeks of gestation with uncontrolled gestational diabetes presents for a routine antenatal checkup. Her fundal height is measured at 36 cm, and her abdominal skin appears excessively stretched and shiny. Previous antenatal ultrasounds were normal. What is the most probable diagnosis?

Polyhydramnios. **Explanation:** The clinical presentation of a fundal height significantly greater than the gestational age (36 cm at 30 weeks), combined with "stretched and shiny" abdominal skin, strongly suggests **Polyhydramnios**. In this case, the underlying etiology is **uncontrolled gestational diabetes mellitus (GDM)**. Maternal hyperglycemia leads to fetal hyperglycemia, which causes osmotic diuresis in the fetus, resulting in fetal polyuria and an increase in amniotic fluid volume. **Why the other options are incorrect:** * **Twin gestation:** While twins also cause a "size > dates" discrepancy, the specific mention of uncontrolled GDM and the classic description of shiny, stretched skin (due to rapid fluid accumulation) points more specifically toward polyhydramnios. Furthermore, previous normal ultrasounds would have already identified a multiple pregnancy. * **Uterine fibroids:** Fibroids can increase fundal height, but they are usually associated with a firm, irregular uterine contour rather than the generalized, tense distension seen here. * **Oligohydramnios:** This would present with a fundal height *less* than the gestational age ("size 25 cm or a Single Deepest Pocket (SDP) > 8 cm. * **Common Causes:** Idiopathic (most common), Maternal Diabetes, Fetal structural anomalies (e.g., Esophageal atresia, Anencephaly), and Rh-isoimmunization. * **Clinical Signs:** Difficulty palpating fetal parts and muffled fetal heart sounds are common findings in severe polyhydramnios. * **Complications:** Increased risk of preterm labor, premature rupture of membranes (PROM), cord prolapse, and postpartum hemorrhage (PPH) due to uterine atony.

Q: A 40-year-old female patient in her third trimester of pregnancy, who is on bed rest, complains of breathlessness. What is the primary risk associated with this patient's condition?

High risk for thrombosis. **Explanation:** The correct answer is **A. High risk for thrombosis.** This patient presents with a "perfect storm" of risk factors for Venous Thromboembolism (VTE), specifically Pulmonary Embolism (PE), which is a leading cause of maternal mortality. The underlying medical concept is **Virchow’s Triad**, which consists of: 1. **Hypercoagulability:** Pregnancy is a naturally hypercoagulable state due to increased clotting factors (I, VII, VIII, IX, X) and decreased protein S activity. 2. **Venous Stasis:** The gravid uterus compresses the inferior vena cava, slowing venous return. Crucially, **bed rest** (immobilization) significantly exacerbates this stasis. 3. **Endothelial Injury:** Though not explicitly mentioned, the physiological changes of pregnancy affect vascular integrity. Furthermore, the patient’s **age (40 years)** is an independent risk factor, as maternal age >35 increases VTE risk. **Analysis of Incorrect Options:** * **B & D:** These are incorrect because pregnancy alone increases the risk of thrombosis by 4–5 times compared to non-pregnant women. Adding immobilization and advanced maternal age makes the risk "high," not "low" or "none." * **C:** "Primary thrombosis" is a vague term. In clinical practice, we categorize the risk based on the severity and the need for thromboprophylaxis. **NEET-PG High-Yield Pearls:** * **Most common site** for DVT in pregnancy: Left leg (due to May-Thurner syndrome-like compression of the left common iliac vein by the right common iliac artery). * **Gold standard investigation** for DVT in pregnancy: Compression Duplex Ultrasound. * **Treatment of choice:** Low Molecular Weight Heparin (LMWH). Warfarin is generally avoided due to teratogenicity (except in specific mechanical valve cases). * **Risk Period:** The highest risk period for VTE is actually the **postpartum period** (puerperium).

Q: What is the most common and most poorly tolerated heart disease during pregnancy?

Aortic stenosis. **Explanation** **Correct Answer: C. Aortic Stenosis** In the context of valvular heart disease during pregnancy, **Aortic Stenosis (AS)** is considered the most poorly tolerated. The underlying pathophysiology involves a fixed cardiac output due to the narrowed aortic valve. Pregnancy normally requires a 30–50% increase in cardiac output; however, patients with AS cannot increase their stroke volume to meet this demand. Furthermore, the physiological peripheral vasodilation of pregnancy leads to decreased systemic vascular resistance, which can cause critical hypotension, reduced coronary perfusion, and sudden cardiac death. **Analysis of Incorrect Options:** * **A. Mitral Stenosis:** While this is the **most common** valvular lesion seen in pregnancy (often due to Rheumatic Heart Disease), it is generally better tolerated than severe AS, provided heart rate and fluid balance are managed to prevent pulmonary edema. * **B. Mitral Regurgitation & D. Aortic Regurgitation:** Regurgitant lesions are actually **well-tolerated** during pregnancy. The physiological decrease in systemic vascular resistance (afterload reduction) and the increase in heart rate help improve forward flow and reduce the regurgitant fraction. **High-Yield Clinical Pearls for NEET-PG:** * **Most common heart disease in pregnancy:** Rheumatic Heart Disease (Mitral Stenosis is the most common lesion). * **Most common congenital heart disease in pregnancy:** Atrial Septal Defect (ASD). * **Highest risk of maternal mortality:** Eisenmenger syndrome (up to 50% mortality), followed by Pulmonary Hypertension and Marfan Syndrome with aortic root involvement. * **Management Tip:** For Aortic Stenosis, maintaining preload is vital; avoid sudden vasodilation or dehydration.

Q: All of the following are indications for Anti-D prophylaxis, EXCEPT:

Intrauterine transfusion at 28 weeks gestation. **Explanation:** The core principle of **Anti-D prophylaxis** is to prevent Rh-isoimmunization in an Rh-negative, non-sensitized mother. It is administered whenever there is a risk of **feto-maternal hemorrhage (FMH)**, where Rh-positive fetal red blood cells enter the maternal circulation. **Why Option C is the Correct Answer:** Intrauterine transfusion (IUT) is performed only when the fetus is **already affected** by Rh-isoimmunization (i.e., the mother is already sensitized and has high antibody titers). Anti-D prophylaxis is a **preventive** measure; it is useless once sensitization has occurred. Therefore, a patient requiring IUT is no longer a candidate for Anti-D. **Analysis of Incorrect Options:** * **A. Medical abortion at 6 weeks:** Any pregnancy termination (spontaneous or induced) after 6 weeks carries a risk of FMH. Anti-D (50 mcg) is indicated. * **B. Amniocentesis at 16 weeks:** Invasive prenatal procedures can cause fetal blood to leak into maternal circulation, necessitating Anti-D administration. * **D. Manual removal of the placenta:** This is a high-risk event for significant FMH. Postpartum Anti-D (300 mcg) must be given within 72 hours of delivery if the neonate is Rh-positive. **High-Yield Clinical Pearls for NEET-PG:** * **Standard Dose:** 300 mcg (1500 IU) covers up to 30 mL of fetal whole blood (or 15 mL of RBCs). * **First Trimester Dose:** 50 mcg is sufficient for events before 12–13 weeks. * **Routine Prophylaxis:** Given at 28 weeks gestation to all non-sensitized Rh-negative women. * **Kleihauer-Betke Test:** Used to quantify the volume of FMH to determine if additional doses of Anti-D are required beyond the standard 300 mcg.

Q: Fetal lung maturity is assessed by ____________

L/S ratio. **Explanation:** The assessment of fetal lung maturity (FLM) is crucial in managing preterm deliveries to prevent Respiratory Distress Syndrome (RDS). **1. Why L/S Ratio is Correct:** The **Lecithin/Sphingomyelin (L/S) ratio** is the gold standard biochemical test for FLM. Lecithin (dipalmitoylphosphatidylcholine) is a major component of surfactant that increases as the lungs mature, while Sphingomyelin levels remain relatively constant. * **Interpretation:** A ratio of **>2.0** generally indicates mature lungs and a low risk of RDS. In diabetic mothers, a higher ratio (often >2.5) or the presence of Phosphatidylglycerol (PG) is required for reassurance. **2. Analysis of Incorrect Options:** * **B. Bilirubin content:** Measured via spectrophotometry (OD450), this is used to assess the severity of **Rh isoimmunization** and fetal hemolysis (Liley’s Chart), not lung maturity. * **C. Ultrasound:** While ultrasound can estimate gestational age and fetal weight, it cannot definitively confirm biochemical lung maturity. * **D. Amniocentesis:** This is the **procedure** used to obtain amniotic fluid, not the test itself. **3. High-Yield Clinical Pearls for NEET-PG:** * **Phosphatidylglycerol (PG):** The most reliable indicator of lung maturity, especially in diabetic pregnancies. Its presence indicates advanced maturity. * **Shake Test (Bubble Stability Test):** A rapid bedside screening test for surfactant. Persistent bubbles after shaking with ethanol indicate maturity. * **Lamellar Body Count (LBC):** A modern, rapid automated test. A count **>30,000–50,000/µL** suggests maturity. * **Corticosteroids:** Administered (Betamethasone/Dexamethasone) between 24–34 weeks to accelerate surfactant production by stimulating Type II pneumocytes.

Q: What can Doppler ultrasound in pregnancy detect?

Intrauterine growth restriction (IUGR). **Explanation:** The correct answer is **D. Intrauterine growth restriction (IUGR).** **Why it is correct:** Doppler ultrasound is a functional imaging tool used to assess **fetal-placental hemodynamics**. In cases of IUGR, placental insufficiency leads to increased resistance in the umbilical artery. Doppler allows clinicians to measure blood flow velocity and resistance indices (like the S/D ratio). As IUGR worsens, one may observe **Absent End-Diastolic Velocity (AEDV)** or **Reversed End-Diastolic Velocity (REDV)** in the umbilical artery, which are critical markers for timing delivery to prevent fetal demise. It also helps identify the "brain-sparing effect" via the Middle Cerebral Artery (MCA) Doppler. **Why other options are incorrect:** * **A, B, and C (Cardiovascular malformations, Neural tube defects, and Abdominal masses):** These are **structural abnormalities**. They are primarily diagnosed using **2D/3D Morphological Ultrasound** (Targeted Imaging for Fetal Anomalies - TIFAL/Level II scan), which visualizes the anatomy rather than the blood flow dynamics. While Color Doppler can assist in fetal echocardiography, the primary screening tool for these malformations is structural B-mode ultrasound. **High-Yield Clinical Pearls for NEET-PG:** * **Umbilical Artery Doppler:** The primary tool for monitoring early-onset IUGR. * **Middle Cerebral Artery (MCA) Doppler:** Used to detect fetal anemia (Peak Systolic Velocity >1.5 MoM) and the brain-sparing effect in hypoxia. * **Ductus Venosus:** Abnormal (A-wave reversal) indicates advanced fetal heart failure and is a late sign of fetal distress. * **Uterine Artery Doppler:** Used at 11–14 weeks to screen for the risk of developing **Pre-eclampsia** (look for persistent "diastolic notch").

Q: Intrauterine fetal death most likely results in which of the following complications?

Hypofibrinogenemia. **Explanation:** **1. Why Hypofibrinogenemia is Correct:** Intrauterine fetal death (IUFD), if the fetus is retained for more than 3–4 weeks, can lead to **Consumptive Coagulopathy (DIC)**. The underlying mechanism involves the gradual release of **thromboplastin** (tissue factor) from the degenerating fetal tissues and placenta into the maternal circulation. This triggers the extrinsic coagulation pathway, leading to the continuous formation of microthrombi and the subsequent depletion of clotting factors, most notably **fibrinogen**. If fibrinogen levels drop below 150 mg/dL, it poses a significant risk of postpartum hemorrhage (PPH). **2. Why Other Options are Incorrect:** * **Cervical Tear:** This is a mechanical complication typically associated with instrumental deliveries (forceps/ventose), precipitate labor, or rigid cervix, rather than the systemic physiological changes of fetal death. * **Sterility:** IUFD does not inherently cause infertility. While complications like severe sepsis or a hysterectomy (due to uncontrollable PPH) could theoretically impact future fertility, they are not direct or "most likely" results of the fetal death itself. **3. NEET-PG High-Yield Pearls:** * **Timeline:** The risk of DIC becomes clinically significant if the dead fetus is retained for **>4 weeks**. * **Initial Investigation:** The first clotting factor to decrease is usually fibrinogen. * **Management:** If DIC is present, it must be corrected with **Fresh Frozen Plasma (FFP)** or Cryoprecipitate before inducing labor. * **Spalding’s Sign:** Overlapping of skull bones (due to liquefaction of the brain) seen on X-ray/USG, usually appearing 4–7 days after death. * **Robert’s Sign:** Appearance of gas in the fetal large vessels (earliest sign, seen within 12 hours).

Q: What are the chances of vertical transmission of Hepatitis B in women who are seropositive for both HBsAg and HBeAg?

90%. **Explanation:** The risk of vertical transmission of Hepatitis B Virus (HBV) is primarily determined by the maternal viral load and serological status. **1. Why 90% is correct:** HBeAg (Hepatitis B envelope antigen) is a marker of active viral replication and high infectivity. When a pregnant woman is positive for both **HBsAg** (indicating infection) and **HBeAg** (indicating high viral load), the risk of vertical transmission to the neonate is approximately **70–90%** in the absence of immunoprophylaxis. Without intervention, about 90% of these infected infants will go on to develop chronic HBV infection. **2. Why other options are incorrect:** * **A & B (25-40%):** These figures are too low for HBeAg-positive mothers. However, if a mother is **HBsAg positive but HBeAg negative** (and anti-HBe positive), the transmission risk drops significantly to about **10–20%**. * **C (60%):** While transmission rates are high, 60% underestimates the synergistic effect of HBeAg positivity on vertical transmission. **3. High-Yield Clinical Pearls for NEET-PG:** * **Timing of Transmission:** Most vertical transmission occurs **intrapartum** (during delivery) due to contact with maternal blood and vaginal secretions. Transplacental (in-utero) transmission is rare ( 200,000 IU/mL (or $10^6$ copies/mL), Tenofovir is recommended starting at 28–32 weeks of gestation to further reduce the viral load. * **Breastfeeding:** It is **not contraindicated** in HBV-positive mothers, provided the infant receives the birth dose of the vaccine and HBIG.

Question 1

A 25-year-old pregnant female at 30 weeks of gestation with uncontrolled gestational diabetes presents for a routine antenatal checkup. Her fundal height is measured at 36 cm, and her abdominal skin appears excessively stretched and shiny. Previous antenatal ultrasounds were normal. What is the most probable diagnosis?

Accepted Answer

Polyhydramnios

Answer

Uterine fibroids

Answer

Twin gestation

Answer

Oligohydramnios

Question 2

A 40-year-old female patient in her third trimester of pregnancy, who is on bed rest, complains of breathlessness. What is the primary risk associated with this patient's condition?

Accepted Answer

High risk for thrombosis

Answer

Low risk for thrombosis

Answer

Risk for primary thrombosis

Answer

No risk for thrombosis

Question 3

What is the most common and most poorly tolerated heart disease during pregnancy?

Accepted Answer

Aortic stenosis

Answer

Mitral stenosis

Answer

Mitral regurgitation

Answer

Aortic regurgitation

Question 4

A primiparous Rh-negative mother has delivered an Rh-positive infant. Administration of which of the following substances is indicated?

Accepted Answer

Anti-D IgG to the mother

Answer

Anti-D IgG to the infant

Answer

Rh-positive red blood cells to the infant

Answer

Rh-positive red blood cells to the mother

Question 5

All of the following are indications for Anti-D prophylaxis, EXCEPT:

Accepted Answer

Intrauterine transfusion at 28 weeks gestation

Answer

Medical abortion at 6 weeks gestation

Answer

Amniocentesis at 16 weeks gestation

Answer

Manual removal of the placenta

Question 6

Fetal lung maturity is assessed by ____________

Accepted Answer

L/S ratio

Answer

Bilirubin content of amniotic fluid

Answer

Ultrasound

Answer

Amniocentesis

Question 7

What can Doppler ultrasound in pregnancy detect?

Accepted Answer

Intrauterine growth restriction (IUGR)

Answer

Cardiovascular malformation

Answer

Neural tube defect

Answer

Abdominal masses

Question 8

Intrauterine fetal death most likely results in which of the following complications?

Accepted Answer

Hypofibrinogenemia

Answer

Cervical tear

Answer

Sterility

Answer

All of the above

Question 9

What are the chances of vertical transmission of Hepatitis B in women who are seropositive for both HBsAg and HBeAg?

Accepted Answer

90%

Answer

25-30%

Answer

40%

Answer

60%

Question 10

Antenatal maternal HIV diagnosis is of importance for what reason?

Accepted Answer

Preventing vertical transmission

Answer

Elective termination of pregnancy

Answer

Discharging the patient from care

Answer

Isolating the patient

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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