Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 451: A non-stress test (NST) performed on a 36-week pregnant diabetic female is non-reactive. What is the recommended next step?

A. Induction of labor
B. Lower segment cesarean section (LSCS)
C. Repeat non-stress test (NST) after 1 hour
D. Proceed to biophysical profile assessment (Correct Answer)

Explanation: **Explanation:** The **Non-Stress Test (NST)** is a screening tool used to assess fetal well-being by observing the fetal heart rate (FHR) response to fetal movement. A **non-reactive NST** (defined as fewer than two accelerations of at least 15 bpm lasting 15 seconds over a 20-minute period) is a sensitive but non-specific finding. It may indicate fetal hypoxia, but it is frequently caused by a **fetal sleep cycle** (which can last up to 40 minutes) or maternal drug use. **Why Option D is correct:** Because a non-reactive NST has a high false-positive rate, it must be followed by a more specific backup test to confirm fetal compromise. The **Biophysical Profile (BPP)** or a **Contraction Stress Test (CST)** are the standard next steps. The BPP evaluates acute (NST, breathing, movement, tone) and chronic (amniotic fluid volume) markers of fetal health, providing a more accurate assessment of whether the fetus is truly in distress. **Why incorrect options are wrong:** * **Options A & B:** Immediate delivery (Induction or LSCS) is premature without confirming fetal distress. Delivering a 36-week fetus unnecessarily increases the risk of respiratory distress syndrome and prematurity-related complications. * **Option C:** While acoustic stimulation can be used to "wake" a fetus, the standard protocol after a confirmed non-reactive 40-minute NST is to proceed to a BPP or CST rather than simply repeating the same test an hour later. **Clinical Pearls for NEET-PG:** * **Most common cause of a non-reactive NST:** Fetal sleep cycle. * **BPP Components:** Tone, Movement, Breathing, NST, and Amniotic Fluid (Mnemonic: **T**he **M**any **B**abies **N**eed **A**ir). * **Modified BPP:** Consists of NST + Amniotic Fluid Index (AFI). * **High-yield:** A BPP score of 8-10 is normal; 4 or less is an indication for delivery.

Question 452: A 35-week pregnant female presents to the emergency department with complaints of headache and blurred vision. Her blood pressure is 170/110 mm Hg. How should this patient be managed?

A. Admit and observe
B. Admit, control blood pressure, and continue pregnancy until term
C. Admit, start magnesium sulfate and antihypertensives, and terminate the pregnancy (Correct Answer)
D. Start antihypertensives and follow up in the outpatient department

Explanation: This patient presents with **Preeclampsia with Severe Features**. The diagnosis is based on a blood pressure of ≥160/110 mm Hg and "imminent symptoms" (headache and blurred vision), indicating end-organ dysfunction. ### **Explanation of the Correct Answer (C)** In cases of preeclampsia with severe features, the definitive treatment is delivery, regardless of gestational age, if the pregnancy is **≥34 weeks**. 1. **Magnesium Sulfate (MgSO₄):** Administered as the drug of choice for seizure prophylaxis (to prevent eclampsia). 2. **Antihypertensives:** Required to reduce the risk of maternal stroke (e.g., Labetalol, Hydralazine, or Nifedipine). 3. **Termination:** Since the patient is at 35 weeks (beyond the 34-week cutoff), the risks of continuing the pregnancy (abruption, eclampsia, HELLP syndrome) outweigh the benefits of fetal prematurity. ### **Why Other Options are Incorrect** * **Option A & B:** Expectant management is contraindicated here. Delaying delivery in severe preeclampsia after 34 weeks increases maternal morbidity without significant fetal benefit. * **Option D:** Outpatient management is never appropriate for severe preeclampsia. These patients require immediate stabilization and monitoring to prevent life-threatening complications. ### **High-Yield Clinical Pearls for NEET-PG** * **Threshold for Delivery:** In Preeclampsia with severe features, deliver at **≥34 weeks**. In Preeclampsia *without* severe features, deliver at **≥37 weeks**. * **Drug of Choice:** MgSO₄ is superior to phenytoin or diazepam for preventing and treating eclamptic seizures. * **Target BP:** The goal of acute antihypertensive therapy is to bring BP down to **140–150/90–100 mm Hg**, not to normal levels, to avoid placental hypoperfusion. * **Antidote:** Always keep **Calcium Gluconate** (10 ml of 10% solution) ready at the bedside when administering MgSO₄.

Question 453: Which of the following is known to prevent intraventricular hemorrhage when given antenatally?

A. Phenobarbital
B. Vitamin K (Correct Answer)
C. Both
D. None

Explanation: **Explanation:** **1. Why Vitamin K is the Correct Answer:** Intraventricular hemorrhage (IVH) is a significant complication in preterm neonates, often linked to a deficiency in vitamin K-dependent clotting factors (II, VII, IX, and X). Vitamin K does not cross the placenta easily; however, antenatal administration to the mother (usually 10 mg IM or IV) shortly before delivery increases fetal levels of these clotting factors. This stabilization of the neonatal coagulation profile helps prevent germinal matrix hemorrhage and subsequent IVH, particularly in deliveries occurring before 32 weeks of gestation. **2. Why Other Options are Incorrect:** * **Phenobarbital:** Historically, phenobarbital was studied for its potential to stabilize neonatal blood pressure and reduce the incidence of IVH. However, large-scale clinical trials and meta-analyses have shown that it does not significantly reduce the risk of IVH and may cause maternal sedation or neonatal respiratory depression. * **Both:** Since phenobarbital has been proven ineffective for this specific indication in modern evidence-based practice, this option is incorrect. **3. NEET-PG Clinical Pearls & High-Yield Facts:** * **Antenatal Corticosteroids:** These are the **most effective** intervention for preventing IVH. They accelerate lung maturity and stabilize the germinal matrix vasculature. * **Magnesium Sulfate:** While primarily used for eclampsia and fetal neuroprotection (to prevent cerebral palsy), it also shows some benefit in reducing the severity of IVH. * **Vitamin K at Birth:** Regardless of antenatal administration, all newborns should receive 1 mg of Vitamin K intramuscularly to prevent **Hemorrhagic Disease of the Newborn (HDN)**. * **Germinal Matrix:** This is the site of origin for IVH in preterm infants due to its highly vascularized but fragile nature.

Question 454: A pregnant woman at 32 weeks gestation presents for routine antenatal checkup. Examination reveals pedal edema and her blood pressure on repeated recordings is 150/100 mm Hg. Her urine protein is 2+. Which of the following will be the first-line drug of choice in this patient?

A. Metoprolol
B. Methyldopa
C. Losartan
D. Nifedipine (Correct Answer)

Explanation: ### Explanation **Diagnosis:** The patient presents with hypertension (BP ≥140/90 mmHg) and proteinuria (2+) after 20 weeks of gestation, which is the classic triad for **Preeclampsia**. **Why Nifedipine is the Correct Answer:** According to the latest **ACOG and NHBPEP guidelines**, Calcium Channel Blockers (specifically **Oral Nifedipine**) and Alpha-agonists (Labetalol) are considered first-line agents for managing hypertension in pregnancy. * **Mechanism:** Nifedipine acts by inhibiting calcium influx into smooth muscle cells, causing peripheral vasodilation. * **Clinical Utility:** It is preferred due to its rapid onset, safety profile for the fetus, and effectiveness in preventing progression to severe hypertension. In many recent protocols (including those followed in NEET-PG patterns), Nifedipine is prioritized for its ease of administration and efficacy. **Why Other Options are Incorrect:** * **A. Metoprolol:** Beta-blockers like Metoprolol are generally avoided as first-line agents due to risks of fetal bradycardia and potential association with Intrauterine Growth Restriction (IUGR). * **B. Methyldopa:** While traditionally the drug of choice, it is now considered a second-line or alternative agent because it has a slow onset of action (4–6 hours) and common side effects like sedation and depression. * **C. Losartan:** ACE inhibitors and ARBs are **strictly contraindicated** in pregnancy (Category X). They cause fetal renal dysgenesis, oligohydramnios, and skull defects. **Clinical Pearls for NEET-PG:** 1. **Drug of Choice for Acute Hypertensive Crisis in Pregnancy:** IV Labetalol or IV Hydralazine. 2. **Drug of Choice for Eclampsia Prophylaxis:** Magnesium Sulfate ($MgSO_4$)—Pritchard Regimen. 3. **Definitive Treatment for Preeclampsia:** Delivery of the fetus and placenta. 4. **Contraindicated Drugs:** ACE inhibitors, ARBs, Sodium Nitroprusside (risk of cyanide toxicity), and Diuretics (unless pulmonary edema is present).

Question 455: A patient delivers a twin gestation in which one infant has blood group O and one has blood group B. The mother and father are both blood group O. How is this discordant blood type scenario explained?

A. Fertilization of a single ovum that splits into two during the same menstrual cycle.
B. Fertilization of two ova within the same menstrual cycle, occurring from separate coitus events. (Correct Answer)
C. Fertilization of two ova separated in time by an interval as long as or longer than a menstrual cycle.
D. This scenario does not occur spontaneously in humans.

Explanation: This scenario describes a case of **Superfecundation**, which is the fertilization of two separate ova by two different sperm during the same menstrual cycle. ### **Explanation of the Correct Answer** In this case, the mother (Group O) and the father (Group O) can only produce an offspring with blood group O (genotype OO). The presence of a twin with blood group B indicates that this twin must have a different biological father who carries the B allele. This occurs via **superfecundation**, specifically **heteropaternal superfecundation** if the coitus events involved different partners. Because the twins have different genetic compositions (discordant blood groups), they are **dizygotic**. ### **Analysis of Incorrect Options** * **Option A (Monozygotic Twins):** Fertilization of a single ovum that splits results in monozygotic (identical) twins. These twins share the exact same genetic material and would always have identical blood groups. * **Option C (Superfetalation):** This refers to the fertilization and implantation of a second ovum when a pregnancy is already established in the uterus (intervals > one cycle). While theoretically possible, it is extremely rare in humans and is not the standard explanation for discordant blood types in a single delivery. * **Option D:** This scenario does occur in humans, often discovered during paternity testing or transplant compatibility screening. ### **NEET-PG High-Yield Pearls** * **Superfecundation:** Two ova, one cycle, two separate acts of coitus (can be same or different father). * **Superfetalation:** Two ova, different cycles (extremely rare in humans). * **Dizygotic Twins:** Always dichorionic/diamniotic; genetically as similar as siblings. * **Blood Group Rule:** Two "O" parents can **only** have "O" children. Any other blood group in the offspring suggests non-paternity or superfecundation.

Question 456: What is the most valuable diagnostic test in the case of a suspected ectopic pregnancy?

A. Serial beta-hCG levels
B. Transvaginal ultrasound (Correct Answer)
C. Progesterone measurement
D. Culdocentesis

Explanation: **Explanation:** The diagnosis of ectopic pregnancy relies on the "Diagnostic Triad" of history (amenorrhea/pain), physical exam, and biochemical/radiological investigations. **Why Transvaginal Ultrasound (TVS) is the correct answer:** TVS is considered the **most valuable diagnostic test** because it provides definitive anatomical localization of the pregnancy. It can visualize an intrauterine gestational sac as early as 4.5–5 weeks. In ectopic pregnancy, TVS can identify an adnexal mass (the "bagel sign" or "tubal ring"), a non-homogenous adnexal mass (most common finding), or even a live extrauterine embryo. When combined with the concept of the **Discriminatory Zone** (hCG level at which an IUP should be visible), TVS becomes the gold standard for diagnosis. **Why other options are incorrect:** * **Serial beta-hCG levels:** While crucial for monitoring viability and determining the discriminatory zone, a single or serial hCG level cannot pinpoint the *location* of the pregnancy. It is a supportive biochemical test, not a definitive diagnostic one. * **Progesterone measurement:** Levels <5 ng/mL suggest a non-viable pregnancy, but they cannot distinguish between a miscarriage and an ectopic pregnancy. It lacks specificity. * **Culdocentesis:** Once a mainstay to detect hemoperitoneum (ruptured ectopic), it is now largely obsolete due to the high sensitivity and non-invasive nature of TVS. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of ectopic:** Ampulla of the Fallopian tube. * **Most common TVS finding:** A non-specific adnexal mass separate from the ovary (seen in ~90% of cases). * **Discriminatory Zone:** Usually **1500–2000 mIU/mL** for TVS. If hCG is above this and the uterus is empty, ectopic pregnancy must be suspected. * **Arias-Stella Reaction:** Endometrial changes (hypersecretory glands) seen in ectopic pregnancy, often confused with malignancy.

Question 457: A woman in her first pregnancy reports that she smokes one pack of cigarettes a day. An ultrasound is ordered in the thirty-second week of the pregnancy to evaluate for which of the following?

A. Amniotic fluid volume
B. Fetal size (Correct Answer)
C. Fetal abnormalities
D. Fetal motion

Explanation: **Explanation:** **1. Why "Fetal size" is the correct answer:** Cigarette smoking during pregnancy is a well-established risk factor for **Fetal Growth Restriction (FGR)**. Nicotine and carbon monoxide in tobacco smoke cause systemic vasoconstriction and increase carboxyhemoglobin levels, leading to chronic placental insufficiency and reduced oxygen delivery to the fetus. This typically results in "asymmetric" growth restriction. Since the risk of FGR increases as the pregnancy progresses, a 32-week ultrasound is specifically indicated to assess fetal biometry (size) and estimated fetal weight to ensure the fetus is growing appropriately for its gestational age. **2. Why the other options are incorrect:** * **Amniotic fluid volume:** While oligohydramnios can be associated with placental insufficiency, it is usually a secondary finding. The primary concern with smoking is the direct impact on fetal weight and size. * **Fetal abnormalities:** Smoking is not a major teratogen associated with structural malformations detectable at 32 weeks. Screening for structural anomalies is ideally performed during the "Level II" anomaly scan at 18–20 weeks. * **Fetal motion:** Fetal movement is a marker of acute fetal well-being (biophysical profile). While important, it is not the specific pathology linked to the chronic vascular effects of smoking. **Clinical Pearls for NEET-PG:** * **Dose-Response Relationship:** The reduction in birth weight is directly proportional to the number of cigarettes smoked (approx. 15–20g reduction per cigarette per day). * **Smoking & Placenta:** Smoking increases the risk of **Placenta Previa** and **Abruptio Placentae**. * **Postnatal Risks:** Maternal smoking is a significant risk factor for **Sudden Infant Death Syndrome (SIDS)** and childhood respiratory infections.

Question 458: Warfarin therapy during the first trimester of pregnancy can lead to which of the following problems?

A. Chondrodysplasia punctata (Correct Answer)
B. Fetal optic atrophy
C. Mental retardation
D. None of the above

Explanation: **Explanation:** Warfarin is a low-molecular-weight anticoagulant that readily crosses the placenta. When administered during the **first trimester** (specifically between **6 to 9 weeks** of gestation), it interferes with the carboxylation of osteocalcin and other bone proteins, leading to a specific constellation of defects known as **Fetal Warfarin Syndrome (Warfarin Embryopathy).** **1. Why Chondrodysplasia Punctata is Correct:** The hallmark of Warfarin Embryopathy is **Chondrodysplasia punctata**, characterized by "stippled epiphyses" (calcific punctations) visible on X-ray. This occurs due to the inhibition of Vitamin K-dependent clotting factors and bone proteins during the critical period of organogenesis. Other features include **nasal hypoplasia** (depressed nasal bridge) and midface hypoplasia. **2. Why Incorrect Options are Wrong:** * **Fetal Optic Atrophy & Mental Retardation:** While these CNS abnormalities can occur with Warfarin use, they are typically associated with exposure during the **second and third trimesters**. CNS damage is usually the result of micro-hemorrhages in fetal neural tissue rather than the primary teratogenic effect seen in the first trimester. Since the question specifically asks for first-trimester problems, Chondrodysplasia punctata is the most specific and classic answer. **High-Yield Clinical Pearls for NEET-PG:** * **Critical Period:** 6–9 weeks of gestation. * **Safe Alternative:** **Heparin** (Unfractionated or LMWH) is the drug of choice in pregnancy because it is a large molecule and **does not cross the placenta**. * **Warfarin in Late Pregnancy:** Use near term can cause fetal/neonatal hemorrhage and placental abruption due to the trauma of labor. * **Breastfeeding:** Warfarin is **safe** during breastfeeding as it is not excreted in breast milk.

Question 459: What criteria are used for diagnosing cervical pregnancy?

A. Studiford
B. Spiegelberg
C. Wrigly
D. Rubin (Correct Answer)

Explanation: **Explanation:** Cervical pregnancy is a rare form of ectopic pregnancy where the blastocyst implants in the cervical canal. The diagnosis is primarily clinical and radiological, based on the **Rubin’s Criteria**. **1. Why Rubin’s Criteria is correct:** Rubin’s criteria (1945) define the pathological requirements for cervical pregnancy: * Cervical glands must be opposite the placental attachment. * The attachment of the placenta to the cervix must be below the level of the entrance of the uterine vessels or below the peritoneal reflection of the anterior and posterior uterine surfaces. * Fetal elements must be absent from the uterine cavity. **2. Analysis of Incorrect Options:** * **Studiford Criteria (Option A):** These are used for the diagnosis of **Primary Abdominal Pregnancy**. * **Spiegelberg Criteria (Option B):** These are the diagnostic criteria for **Ovarian Pregnancy**. * **Wrigley’s (Option C):** This refers to **Wrigley’s Forceps**, which are outlet forceps used to assist delivery when the head is on the perineum. **3. Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Characterized by painless, profuse vaginal bleeding. On examination, the cervix appears "hourglass" shaped or distended (ballooned). * **Ultrasonography (Palman’s Criteria):** Key findings include an empty uterine cavity, a "sandglass" shaped uterus, and a gestational sac in the cervix. * **Management:** Historically required hysterectomy due to uncontrollable bleeding; however, modern management includes **Systemic or Intra-amniotic Methotrexate** and uterine artery embolization to preserve fertility.

Question 460: What is the normal weight of a term placenta in grams?

A. 300
B. 500 (Correct Answer)
C. 700
D. 1000

Explanation: **Explanation:** The placenta is a vital discoid organ that facilitates nutrient and gas exchange between the mother and the fetus. At full term (37–42 weeks), a healthy placenta typically weighs approximately **500 grams**, which is the standard value used in clinical obstetrics and competitive exams like NEET-PG. **Why 500g is correct:** The weight of the placenta is generally proportional to the weight of the fetus. At term, the average fetal weight is approximately 3000–3500g. The **feto-placental weight ratio** at term is approximately **6:1**. Therefore, for a 3kg baby, the placenta weighs roughly 500g (1/6th of the birth weight). **Analysis of Incorrect Options:** * **A. 300g:** This is considered underweight for a term placenta. It may be seen in cases of placental insufficiency, severe pre-eclampsia, or intrauterine growth restriction (IUGR). * **C. 700g:** This is heavier than normal (placentomegaly). It may be associated with maternal diabetes mellitus or certain congenital infections (TORCH). * **D. 1000g:** A placenta this large is highly pathological. It is characteristically seen in cases of **Hydrops Fetalis**, severe Rh-isoimmunization, or massive placental edema. **High-Yield Clinical Pearls for NEET-PG:** * **Dimensions:** A term placenta is roughly 15–20 cm in diameter and 3 cm in thickness at its center. * **Surface Area:** The total surface area of the chorionic villi for exchange is approximately 10–14 square meters. * **Volume:** The total amount of blood in a term placenta is about 500 ml (divided between the fetal and maternal sides). * **Placentomegaly:** Defined as a placental thickness >4 cm before 24 weeks or a weight exceeding the 90th percentile for gestational age.

Practice by Chapter

Fetal Assessment Techniques

Practice Questions

Hypertensive Disorders in Pregnancy

Practice Questions

Intrauterine Growth Restriction

Practice Questions

Multiple Gestation

Practice Questions

Rh Isoimmunization and Other Blood Group Incompatibilities

Practice Questions

Intrauterine Fetal Therapy

Practice Questions

Prenatal Diagnosis and Genetic Counseling

Practice Questions

Placental Abnormalities

Practice Questions

Preterm Labor and Delivery

Practice Questions

Management of Medical Disorders in Pregnancy

Practice Questions

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