Maternal-Fetal Medicine Practice Questions

Q: What is the recommended mode of delivery for a case of central placenta previa with an anencephaly fetus?

Cesarean section. **Explanation:** In cases of **central (Type IV) placenta previa**, the placenta completely covers the internal os. This creates an absolute mechanical obstruction to the birth canal, making vaginal delivery impossible regardless of the fetal condition. 1. **Why Cesarean Section is Correct:** Even though the fetus has a lethal anomaly (anencephaly), the primary concern in central placenta previa is **maternal safety**. Attempting a vaginal delivery would lead to massive, life-threatening maternal hemorrhage as the cervix dilates and separates the placenta. Therefore, a Cesarean section is mandatory to bypass the obstruction and control bleeding, even if the fetus is non-viable. 2. **Why Incorrect Options are Wrong:** * **Induction of Labor:** Induction is contraindicated because the placenta blocks the exit. Uterine contractions against a central previa will cause catastrophic antepartum hemorrhage. * **Breech Extraction/Forceps:** These are methods of vaginal instrumental delivery. Since the fetus cannot enter the birth canal due to the placental position, these maneuvers are physically impossible and would cause fatal trauma and hemorrhage. **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Indications for C-Section in Placenta Previa:** Type II posterior (Dangerous Type), Type III, and Type IV (Central). * **Anencephaly & Delivery:** Normally, for a lethal anomaly like anencephaly, vaginal delivery is preferred to avoid maternal morbidity from surgery. However, **Placenta Previa is the "Exception to the Rule"**—maternal life always takes precedence over fetal condition. * **Double Setup Examination:** This is no longer routinely recommended; diagnosis is primarily via Transvaginal Ultrasound (TVS).

Q: What period carries the highest risk of HIV transmission?

During vaginal delivery. **Explanation:** The risk of Mother-to-Child Transmission (MTCT) of HIV occurs at three distinct stages: antepartum (in utero), intrapartum (during labor and delivery), and postpartum (via breastfeeding). **Why Option C is correct:** The **intrapartum period** (during vaginal delivery) carries the highest risk of transmission, accounting for approximately **60-75%** of cases in non-breastfeeding women. This is due to "micro-transfusions" occurring during uterine contractions and the direct exposure of the fetus to infected maternal blood and cervicovaginal secretions in the birth canal. **Analysis of Incorrect Options:** * **A. Caesarean Section:** Elective (pre-labor) C-section actually *reduces* the risk of transmission by avoiding the birth canal and labor contractions. It is recommended if the maternal viral load is >1000 copies/mL. * **B. Antepartum Period:** While transmission can occur via the placenta, it accounts for only about **20-25%** of cases, primarily occurring in the late third trimester. * **D. Breastfeeding:** This contributes to roughly **10-15%** of the total risk if the mother is not on ART. While significant, the cumulative risk is lower than the acute risk during the intrapartum window. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Distribution:** Without intervention, the risk is roughly 15-25% in non-breastfeeding women and 25-45% in breastfeeding women. * **Most Important Predictor:** Maternal **plasma viral load** is the strongest predictor of transmission risk. * **Zidovudine (AZT):** Historically the cornerstone of prevention; however, current WHO/NACO guidelines recommend **Life-long ART (TLD regimen)** for all pregnant and breastfeeding women regardless of CD4 count (Option B+ strategy). * **Infant Prophylaxis:** In India, Nevirapine syrup is typically given to the infant for 6 weeks.

Q: Which of the following antihypertensives is NOT used in the management of pregnancy-induced hypertension in the first trimester?

Atenolol. **Explanation:** The management of hypertension in pregnancy requires balancing maternal blood pressure control with fetal safety. **Atenolol** is generally avoided in pregnancy, particularly in the first trimester, because it is associated with **fetal growth restriction (FGR)**, placental weight reduction, and potential neonatal complications like bradycardia and hypoglycemia. Unlike other beta-blockers, atenolol’s specific association with significant intrauterine growth restriction makes it a suboptimal choice compared to safer alternatives. **Analysis of Options:** * **Labetalol (Option C):** This is the **first-line drug of choice** for chronic and gestational hypertension. It is a combined alpha and beta-blocker with a proven safety profile throughout pregnancy. * **Nifedipine (Option D):** A calcium channel blocker (long-acting formulation) frequently used as a first-line or second-line agent. It is safe and effective for long-term management. * **Hydralazine (Option A):** A direct vasodilator primarily used for the acute management of **hypertensive emergencies** in pregnancy (e.g., severe preeclampsia). While not first-line for routine control, it is not contraindicated. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** Labetalol is the overall DOC for hypertension in pregnancy. * **Acute Hypertensive Crisis:** IV Labetalol or IV Hydralazine are preferred. * **Absolute Contraindications:** **ACE Inhibitors** (e.g., Enalapril) and **ARBs** (e.g., Losartan) are strictly contraindicated as they cause fetal renal dysgenesis, oligohydramnios, and skull defects. * **Methyldopa:** Historically the DOC; it remains a safe option but is now often considered second-line due to its slow onset and side-effect profile (sedation).

Q: Which of the following is true for the ratio of fresh placental weight to infant weight in the last trimester of pregnancy?

1:6. The placental-fetal weight ratio is a critical indicator of placental efficiency and fetal growth. In a healthy, term pregnancy, the placenta weighs approximately **one-sixth** of the infant's weight. ### **Detailed Explanation** 1. **Correct Answer (C): 1:6** At full term (approx. 40 weeks), a normal placenta weighs about **500 grams**, while a healthy newborn weighs approximately **3000–3500 grams**. This results in a ratio of roughly **1:6**. This ratio is not constant throughout pregnancy; the placenta is actually heavier than the fetus in early gestation, but the fetus grows at a much faster rate during the third trimester, leading to the 1:6 ratio at term. 2. **Incorrect Options (A, B, D):** * **1:2 (A):** This ratio would imply a massive placenta (e.g., a 1.5kg placenta for a 3kg baby), which is pathological and seen only in severe cases of hydrops fetalis or congenital syphilis. * **2:1 and 6:1 (B, D):** These ratios suggest the placenta is significantly heavier than the baby. While the placenta is heavier than the embryo in the first trimester (around 10-12 weeks), these ratios are never seen in the third trimester. ### **NEET-PG High-Yield Pearls** * **Placental Weight:** Approximately 500g at term (1/6th of fetal weight). * **Placental Diameter:** 15–20 cm; **Thickness:** 2.5–3 cm at the center. * **Increased Ratio (>1:6):** Seen in **Diabetes Mellitus**, Rh-isoimmunization (Hydrops), Syphilis, and Multiple gestations. A "large" placenta often indicates a need for increased surface area to compensate for poor oxygen transfer. * **Decreased Ratio (<1:6):** Seen in **Preeclampsia**, chronic hypertension, and severe IUGR, where placental insufficiency leads to a small, infarcted placenta. * **Number of Cotyledons:** 15–20 lobes (functional units).

Q: A 24-year-old pregnant woman at 36 weeks gestation presents with sudden onset headache and blurred vision. Her blood pressure is 170/110 mm Hg. Urinalysis reveals albumin +++ and fundus examination shows retinal hemorrhages. What is the most appropriate next step in management?

Anticonvulsive therapy. **Explanation:** The patient presents with the classic triad of **Severe Preeclampsia**: severe hypertension (≥160/110 mm Hg), significant proteinuria (+++), and "imminent symptoms" (headache, visual disturbances, and retinal hemorrhages). These symptoms indicate cerebral and retinal edema, signaling that the patient is at high risk for progressing to **Eclampsia** (seizures). **Why Anticonvulsive Therapy is Correct:** In the management of severe preeclampsia, the immediate priority is the **prevention of seizures** and stabilization of the mother. **Magnesium Sulfate (MgSO₄)** is the drug of choice for seizure prophylaxis. While delivery is the definitive cure for preeclampsia, the patient must be stabilized first with anticonvulsants and antihypertensives to prevent life-threatening complications like intracranial hemorrhage or status epilepticus during the delivery process. **Why Other Options are Incorrect:** * **A. Conservative treatment:** This is contraindicated in severe preeclampsia at 36 weeks. Delaying treatment increases the risk of maternal stroke, placental abruption, and fetal demise. * **C & D. Induction of labor / Cesarean delivery:** While delivery is the ultimate treatment, it is the *second* step. You must "stabilize then deliver." Performing a delivery or induction without first administering MgSO₄ and controlling blood pressure puts the patient at maximum risk for intrapartum eclampsia. **NEET-PG High-Yield Pearls:** * **Drug of Choice:** Magnesium Sulfate (Pritchard Regimen or Zuspan Regimen). * **Therapeutic Level of MgSO₄:** 4–7 mEq/L. * **First Sign of Toxicity:** Loss of patellar reflex (Knee jerk). * **Antidote:** Calcium Gluconate (10 ml of 10% solution IV). * **Target BP:** Aim to lower MAP by 20-25%, maintaining diastolic BP between 90-100 mm Hg to prevent placental hypoperfusion.

Q: What is the most common complication due to expectant management of preeclampsia?

Placental abruption. **Explanation:** The goal of expectant management in preeclampsia (typically practiced between 24 and 34 weeks of gestation) is to improve neonatal outcomes by allowing for fetal growth and lung maturation. However, this prolongs exposure to a pathophysiological state characterized by systemic vasospasm and endothelial dysfunction. **Why Placental Abruption is the Correct Answer:** Placental abruption is the **most common maternal complication** associated with the expectant management of preeclampsia. The underlying mechanism involves chronic placental ischemia and high systemic vascular resistance, which leads to rupture of the maternal spiral arteries into the decidua basalis. Studies indicate that in patients undergoing expectant management for severe preeclampsia, the incidence of abruption is significantly higher compared to the general obstetric population. **Analysis of Incorrect Options:** * **A. Acute Renal Failure:** While preeclampsia causes glomerular endotheliosis and reduced GFR, frank acute renal failure is less common than abruption unless complicated by HELLP syndrome or massive hemorrhage. * **B. Pulmonary Edema:** This is a life-threatening complication usually triggered by iatrogenic fluid overload or left ventricular failure, but it occurs less frequently than abruption. * **C. Cardiac Arrest:** This is an extremely rare, terminal event and not a standard "common" complication of expectant management. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of death in Preeclampsia:** Cerebral Hemorrhage (Stroke). * **Most common maternal complication of expectant management:** Placental Abruption. * **Indication for immediate delivery:** Signs of maternal/fetal deterioration (e.g., eclampsia, persistent severe headache, pulmonary edema, or non-reassuring CTG) regardless of gestational age. * **Drug of choice for seizure prophylaxis:** Magnesium Sulfate ($MgSO_4$).

Question 1

What is the recommended mode of delivery for a case of central placenta previa with an anencephaly fetus?

Accepted Answer

Cesarean section

Answer

Induction of labor

Answer

Breech extraction

Answer

Application of forceps

Question 2

What period carries the highest risk of HIV transmission?

Accepted Answer

During vaginal delivery

Answer

During Caesarean section

Answer

During the antepartum period

Answer

Breastfeeding

Question 3

Which of the following antihypertensives is NOT used in the management of pregnancy-induced hypertension in the first trimester?

Accepted Answer

Atenolol

Answer

Hydralazine

Answer

Labetalol

Answer

Nifedipine

Question 4

Which of the following is true for the ratio of fresh placental weight to infant weight in the last trimester of pregnancy?

Accepted Answer

1:6

Answer

1:2

Answer

2:1

Answer

6:1

Question 5

A 24-year-old pregnant woman at 36 weeks gestation presents with sudden onset headache and blurred vision. Her blood pressure is 170/110 mm Hg. Urinalysis reveals albumin +++ and fundus examination shows retinal hemorrhages. What is the most appropriate next step in management?

Accepted Answer

Anticonvulsive therapy

Answer

Conservative treatment

Answer

Induction of labor

Answer

Cesarean delivery

Question 6

A 34-week pregnant woman, G3P2L2, complains of decreased fetal movements for the past 24 hours. She has no other significant pregnancy-related conditions. What is the next best step?

Accepted Answer

Instruct the patient to go to the hospital for a nonstress test.

Answer

Instruct the patient to go to the hospital for a contraction stress test.

Answer

Reassure the patient that one fetal movement per hour is within normal limits.

Answer

Admit the patient to the hospital for delivery.

Question 7

Regarding HIV transmission to the fetus, all statements are true except?

Accepted Answer

Can present as failure to thrive

Answer

More than 50% risk of transmission to the fetus

Answer

Greatest risk of transmission is in the perinatal period

Answer

Cannot be diagnosed

Question 8

In a primigravida with mechanical heart valves, at which gestational week is intravenous heparin typically introduced?

Accepted Answer

36 weeks

Answer

32 weeks

Answer

40 weeks

Answer

At the time of labor

Question 9

What is the most common complication due to expectant management of preeclampsia?

Accepted Answer

Placental abruption

Answer

Acute renal failure

Answer

Pulmonary edema

Answer

Cardiac arrest

Question 10

Which of the following is NOT a cause of intrauterine fetal death?

Accepted Answer

Pregnancy-induced hypertension (PIH)

Answer

Disseminated intravascular coagulation (DIC)

Answer

Psychological upset

Answer

Infection

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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