Maternal-Fetal Medicine Practice Questions

Q: On TVS, which of the following shapes of the cervix indicates preterm labor?

U shape. **Explanation:** The assessment of cervical morphology via Transvaginal Sonography (TVS) is a critical predictor of preterm labor. The process of cervical effacement occurs through a predictable sequence of structural changes known by the mnemonic **"TRUST"** (T → Y → V → U). 1. **Correct Answer (C):** The **U shape** represents the final stage of cervical funneling. In this stage, the internal os has opened significantly, and the cervical canal has shortened drastically, leaving only a small portion of the distal cervix closed. This indicates advanced cervical ripening and carries the highest risk for imminent preterm delivery. 2. **Incorrect Options:** * **T shape (A):** This is the normal appearance of a closed, long cervix. The internal os is flat, indicating no funneling and a low risk of preterm labor. * **Y shape (B):** This represents the earliest stage of funneling, where the internal os begins to open slightly while the rest of the canal remains closed. * **V shape:** (Though not an option, it follows 'Y') This indicates deeper funneling toward the external os. * **O shape (D):** This is not a standard sonographic term used to describe the progression of cervical funneling in the context of preterm labor. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard:** TVS is superior to transabdominal ultrasound for measuring cervical length. * **Critical Cut-off:** A cervical length of ** 5 mm. * **Management:** If a short cervix is detected early, interventions include vaginal progesterone or cervical cerclage (e.g., McDonald or Shirodkar technique).

Q: Which of the following is not a predisposing factor for Preeclampsia?

Smoking. **Explanation:** Preeclampsia is a multisystem disorder characterized by new-onset hypertension and proteinuria after 20 weeks of gestation. Understanding its risk factors is crucial for NEET-PG. **Why Smoking is the Correct Answer:** Counter-intuitively, **smoking is a protective factor** against preeclampsia (reducing risk by approximately 30-50%). The underlying medical concept involves the stimulation of placental growth factor (PlGF) and the inhibition of soluble fms-like tyrosine kinase-1 (sFlt-1) by carbon monoxide and nicotine. This helps maintain a pro-angiogenic balance, preventing the endothelial dysfunction typical of preeclampsia. **Analysis of Incorrect Options:** * **Anti-phospholipid antibody (APLA):** This is a major risk factor. APLA syndrome causes placental thrombosis and impaired trophoblastic invasion, leading to placental ischemia and early-onset preeclampsia. * **Gestational Diabetes (GDM):** Hyperinsulinemia and insulin resistance are associated with systemic inflammation and endothelial damage, significantly increasing the risk of hypertensive disorders. * **Molar Pregnancy:** This is a classic "high-yield" risk factor. The excessive trophoblastic proliferation leads to the release of anti-angiogenic factors. Notably, preeclampsia occurring **before 20 weeks** should always raise suspicion of a hydatidiform mole. **Clinical Pearls for NEET-PG:** * **Highest Risk Factor:** A prior history of preeclampsia is the strongest predictor. * **Nulliparity:** Often called the "disease of theories," it is most common in first pregnancies. * **Protective Factors:** Smoking and previous term delivery with a different partner (though the latter is debated). * **Prophylaxis:** Low-dose Aspirin (75–150 mg) started before 16 weeks is recommended for high-risk patients.

Q: What is the typical volume of amniotic fluid at 38 weeks of gestation in a normal pregnancy?

800 cc. **Explanation:** The volume of amniotic fluid is a dynamic indicator of fetal well-being and follows a characteristic pattern of increase and decrease throughout pregnancy. **1. Why 800 cc is correct:** Amniotic fluid volume increases progressively from the first trimester. It reaches its peak volume of approximately **800–1000 mL at 36–38 weeks** of gestation. After 38 weeks, the volume begins to decline physiologically. By 40 weeks (term), it reduces to about 600–800 mL, and if the pregnancy continues to 42 weeks (post-term), it may drop significantly to around 200–400 mL. **2. Analysis of incorrect options:** * **B (1100 cc):** This is slightly above the normal peak range. While individual variations exist, 800 cc is the standard textbook value for 38 weeks. * **C & D (1500 cc and 1800 cc):** These values are pathologically high. A volume exceeding 1500–2000 mL (or an Amniotic Fluid Index > 25 cm) is defined as **Polyhydramnios**, which can be associated with maternal diabetes or fetal anomalies like esophageal atresia. **High-Yield Clinical Pearls for NEET-PG:** * **Source:** Early pregnancy fluid is an ultrafiltrate of maternal plasma; after 20 weeks, **fetal urine** becomes the primary contributor. * **Measurement:** Clinically assessed via USG using the **Amniotic Fluid Index (AFI)**. Normal AFI is 5–24 cm. * **Oligohydramnios:** Defined as a volume < 200 mL at term or an AFI < 5 cm. Often associated with renal agenesis (Potter sequence) or placental insufficiency. * **Specific Gravity:** Approximately 1.008–1.010; it becomes more hypotonic as the fetus nears term due to increased fetal dilute urine.

Q: What is the approximate percentage decrease in the chance of transmission of HIV to a fetus during pregnancy with the use of antiretroviral prophylaxis?

65%. The correct answer is **D. 65%**. ### **Explanation** The risk of vertical transmission of HIV from mother to child without any intervention is approximately **25–30%**. The landmark **PACTG 076 trial** established that the administration of Zidovudine (AZT) monotherapy during pregnancy, labor, and to the newborn reduces this risk by approximately **two-thirds (66-67%)**, bringing the transmission rate down to about 8%. In modern clinical practice, with Highly Active Antiretroviral Therapy (HAART) and viral load suppression to undetectable levels, the risk can be further reduced to **less than 1%**. However, in the context of standard prophylaxis (as often tested in exams based on classic trials), the 65% reduction is the benchmark figure. ### **Analysis of Incorrect Options** * **A, B, and C:** These percentages (35%, 45%, 50%) underestimate the efficacy of antiretroviral prophylaxis. While any ART provides some benefit, the established clinical standard for the *decrease in risk* is significantly higher than 50%. ### **High-Yield Clinical Pearls for NEET-PG** * **Most common route of transmission:** Intrapartum (during labor and delivery) is the period of highest risk. * **Preferred Regimen (India/WHO):** TLE regimen (Tenofovir + Lamivudine + Efavirenz) was the standard; however, newer guidelines favor **Dolutegravir (DTG)** based regimens. * **Breastfeeding:** In resource-limited settings (like India), exclusive breastfeeding for the first 6 months is recommended if the mother is on ART, as the benefits of nutrition/immunity outweigh the risk of HIV transmission. * **Mode of Delivery:** Elective Cesarean Section (at 38 weeks) is indicated if the maternal viral load is **>1000 copies/mL** near term to further reduce transmission. * **Neonatal Prophylaxis:** Nevirapine syrup is typically given to the infant for 6 weeks (extendable to 12 weeks in high-risk cases).

Q: In which period of pregnancy is cordiocentesis typically performed?

18-20 weeks. **Explanation:** **Cordocentesis**, also known as Percutaneous Umbilical Blood Sampling (PUBS), is an invasive prenatal diagnostic procedure used to obtain fetal blood directly from the umbilical vein. **Why 18-20 weeks is the correct answer:** The procedure is typically performed after **18 weeks** of gestation. Before this period, the umbilical vein is technically too small and fragile to puncture safely, and the risk of procedure-related pregnancy loss is significantly higher. By 18–20 weeks, the vessel diameter is sufficient to allow for ultrasound-guided needle insertion (usually at the placental insertion site of the cord) with a higher success rate and lower risk of fetal bradycardia or hemorrhage. **Analysis of Incorrect Options:** * **A. 11-14 weeks:** This is the window for Chorionic Villus Sampling (CVS) and Nuchal Translucency (NT) scans. Cordocentesis is not feasible here due to the minute size of the umbilical cord. * **C & D. 22-30 weeks:** While cordocentesis *can* be performed later in pregnancy (e.g., for fetal anemia or late-onset growth restriction), it is not the "typical" or earliest recommended window for primary diagnostic purposes. Non-invasive methods or amniocentesis are often preferred if possible during these stages. **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Rapid karyotyping (results in 48–72 hours), diagnosis of fetal infections (e.g., Toxoplasmosis, CMV), and management of Rh-isoimmunization (fetal hemoglobin/hematocrit assessment and intrauterine transfusion). * **Complication:** The most common complication is **fetal bleeding** from the puncture site. * **Comparison:** Amniocentesis is typically done at 15–20 weeks; CVS at 10–13 weeks. Cordocentesis has the highest procedure-related loss rate (~1-2%) among the three.

Q: What does the CTG graph shown in the image indicate regarding fetal heart rate patterns?

A deceleration in the cardiotocography trace. ***A deceleration in the cardiotocography trace*** - A **deceleration** represents a transient fall in **fetal heart rate (FHR)** below the baseline, indicating potential **fetal hypoxia** or **uteroplacental insufficiency**. - Decelerations are classified as **early**, **late**, or **variable** based on their timing relative to **uterine contractions** and require immediate evaluation. *An acceleration in the cardiotocography trace* - **Accelerations** are transient increases in FHR above baseline, typically indicating **fetal well-being** and adequate **oxygenation**. - They are considered **reassuring signs** on CTG monitoring, not concerning patterns requiring intervention. *Insufficient information to determine fetal well-being* - CTG provides continuous monitoring of **fetal heart rate** and **uterine activity**, offering valuable information about fetal status. - Modern CTG technology provides sufficient data to assess **fetal well-being** through pattern recognition and trend analysis. *A normal cardiotocography tracing* - A **normal CTG** shows baseline FHR between **110-160 bpm** with moderate **variability** and **accelerations** present. - Normal tracings are **reassuring** and do not indicate pathological fetal heart rate patterns requiring intervention.

Question 1

On TVS, which of the following shapes of the cervix indicates preterm labor?

Accepted Answer

U shape

Answer

T shape

Answer

Y shape

Answer

O shape

Question 2

Which of the following is not a predisposing factor for Preeclampsia?

Accepted Answer

Smoking

Answer

Anti-phospholipid antibody

Answer

Gestational diabetes

Answer

Molar pregnancy

Question 3

A 38-year-old pregnant woman presents with severe vaginal bleeding. Ultrasound confirms placenta previa. What is the characteristic site of implantation in placenta previa?

Accepted Answer

Lower part of the uterine body, overlapping the internal cervical os

Answer

Uterine (fallopian) tubes

Answer

Cervix

Answer

Mesentery of the abdominal wall

Question 4

What is the typical volume of amniotic fluid at 38 weeks of gestation in a normal pregnancy?

Accepted Answer

800 cc

Answer

1100 cc

Answer

1500 cc

Answer

1800 cc

Question 5

Which of the following statements is true regarding umbilical artery Doppler?

Accepted Answer

Absence of end-diastolic flow is normal at term.

Answer

Changes in the flow velocity waveforms of the umbilical artery may be important in the management of high-risk pregnancies.

Answer

Maternal smoking decreases the S/D ratio.

Answer

Increased diastolic flow indicates a worse prognosis.

Question 6

All of the following are true with regards to fetal lung maturity except?

Accepted Answer

L:S ratio is the single best indicator of pulmonary maturity.

Answer

Phosphatidyl choline is the most important part of surfactant.

Answer

More than 50% cells are orange in colour on Nile blue sulphate test.

Answer

Phosphatidyl glycerol in amniotic fluid is 100% confirmatory of lung maturity.

Question 7

What is the approximate percentage decrease in the chance of transmission of HIV to a fetus during pregnancy with the use of antiretroviral prophylaxis?

Accepted Answer

65%

Answer

35%

Answer

45%

Answer

50%

Question 8

In which period of pregnancy is cordiocentesis typically performed?

Accepted Answer

18-20 weeks

Answer

11-14 weeks

Answer

22-26 weeks

Answer

28-30 weeks

Question 9

What does the CTG graph shown in the image indicate regarding fetal heart rate patterns?

Accepted Answer

A deceleration in the cardiotocography trace

Answer

An acceleration in the cardiotocography trace

Answer

Insufficient information to determine fetal well-being

Answer

A normal cardiotocography tracing

Question 10

Which of the following is seen in pregnancy with heart disease, which is not seen in normal pregnancy?

Accepted Answer

Distended neck veins

Answer

Exertional dyspnea

Answer

Pedal edema

Answer

Supine hypotension

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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