Maternal-Fetal Medicine Practice Questions

Q: Which of the following has proven to be effective in the management of preeclampsia?

Calcium. **Explanation:** The correct answer is **Calcium**. The management of preeclampsia involves two distinct strategies: **prevention** (prophylaxis) and **treatment** of complications. 1. **Why Calcium is correct:** According to WHO and ACOG guidelines, calcium supplementation (1.5–2.0 g/day) is proven to **reduce the risk of developing preeclampsia**, particularly in populations with low dietary calcium intake. The underlying mechanism involves the suppression of parathyroid hormone release and intracellular calcium reduction, which decreases vascular smooth muscle reactivity and prevents hypertension. 2. **Why other options are incorrect:** * **Magnesium:** While **Magnesium Sulfate (MgSO₄)** is the drug of choice for the *prevention and treatment of seizures* (eclampsia), it does not prevent the onset of preeclampsia itself. The question asks for the management of the condition broadly; in the context of nutritional/preventative interventions, calcium has the strongest evidence base. * **Zinc:** Various studies have evaluated antioxidants and minerals like Zinc, Vitamin C, and Vitamin E. However, clinical trials have failed to show any significant benefit in the prevention or management of preeclampsia. **High-Yield Clinical Pearls for NEET-PG:** * **Low-dose Aspirin (75–150 mg):** The most effective pharmacological intervention for preventing preeclampsia in high-risk women, ideally started before 16 weeks of gestation. * **Definitive Treatment:** Delivery of the fetus and placenta remains the only definitive cure for preeclampsia. * **Antihypertensives of choice:** Labetalol (first line), Hydralazine, and Nifedipine. **ACE inhibitors and ARBs are contraindicated** due to teratogenicity.

Q: What is the effect of preeclampsia on the glomerular filtration rate?

Decreases. **Explanation:** In a normal pregnancy, the Glomerular Filtration Rate (GFR) typically increases by 40–50% due to increased plasma volume and renal blood flow. However, in **preeclampsia**, the underlying pathophysiology is systemic endothelial dysfunction and vasospasm. The characteristic renal lesion in preeclampsia is **Glomerular Endotheliosis**. This involves swelling of the glomerular endothelial cells and subendothelial deposits of fibrin-like material, which physically narrows the capillary lumens and reduces the surface area available for filtration. Consequently, renal plasma flow decreases and the **GFR decreases** (typically by 30–40% compared to normal pregnancy levels). This reduction in GFR leads to an increase in serum uric acid (an early marker) and, in severe cases, elevated serum creatinine. **Analysis of Options:** * **A. Increases:** This is incorrect. While GFR increases in a healthy pregnancy, the pathological changes of preeclampsia reverse this trend. * **C. Remains the same:** This is incorrect. The structural damage (endotheliosis) and vasospasm significantly alter renal hemodynamics. * **D. May increase or decrease:** This is incorrect. The physiological hallmark of preeclampsia is a consistent reduction in GFR compared to the expected hyperfiltration of pregnancy. **NEET-PG High-Yield Pearls:** * **Glomerular Endotheliosis** is the pathognomonic renal lesion of preeclampsia. * **Hyperuricemia** (due to decreased GFR and increased tubular reabsorption) is often the first biochemical sign and correlates with the severity of the disease. * Proteinuria in preeclampsia is primarily due to increased glomerular permeability to proteins. * Unlike most renal diseases, the filtration fraction in preeclampsia is often decreased because the reduction in GFR is more pronounced than the reduction in renal plasma flow.

Q: Which of the following side-effects is NOT associated with the use of magnesium sulfate in pregnancy?

Bradycardia. **Explanation:** Magnesium sulfate ($MgSO_4$) is the drug of choice for seizure prophylaxis in pre-eclampsia and management of eclampsia. It acts as a CNS depressant and a calcium antagonist at the neuromuscular junction. **Why Bradycardia is the correct answer:** While $MgSO_4$ has significant cardiovascular effects at toxic levels, it typically causes **tachycardia** (due to peripheral vasodilation and compensatory mechanisms) or hypotension. Bradycardia is not a characteristic side effect; instead, toxicity leads to **cardiac arrest** in asystole at very high serum concentrations (>25–30 mEq/L). **Analysis of incorrect options:** * **Muscular paralysis:** Magnesium inhibits the release of acetylcholine at the motor endplate. Toxicity manifests as a loss of deep tendon reflexes (7–10 mEq/L), progressing to generalized muscle paralysis. * **Cardiac arrhythmias:** At toxic levels (above 15 mEq/L), magnesium causes conduction delays, leading to EKG changes (prolonged PR/QRS intervals) and potentially fatal arrhythmias. * **Respiratory depression:** This is a critical sign of toxicity (12–15 mEq/L) occurring due to the paralysis of respiratory muscles. **High-Yield NEET-PG Pearls:** 1. **Therapeutic Range:** 4–7 mEq/L. 2. **Sequence of Toxicity:** Loss of Patellar Reflex (earliest sign) → Respiratory Depression → Cardiac Arrest. 3. **Monitoring:** Always check urine output (>30 ml/hr), respiratory rate (>12/min), and patellar reflexes before each dose. 4. **Antidote:** 10 ml of 10% **Calcium Gluconate** IV (administered over 10 minutes).

Q: A sinusoidal heart rate pattern is most commonly associated with which of the following conditions?

Vasa previa. **Explanation:** A **sinusoidal heart rate pattern** is a Category III fetal heart rate (FHR) tracing characterized by a smooth, sine-wave-like undulating pattern with a frequency of 3–5 cycles per minute and an amplitude of 5–15 bpm. It is a classic sign of **severe fetal anemia** or acute fetal hypoxia. **Why Vasa Previa is correct:** In vasa previa, fetal vessels run unprotected by Wharton's jelly across the internal os. When the membranes rupture (ROM), these vessels can lacerate, leading to immediate **fetal exsanguination**. Because the fetus has a small blood volume, rapid blood loss leads to severe anemia and hypoxia, manifesting on the CTG as a sinusoidal pattern. This is a surgical emergency. **Why the other options are incorrect:** * **Placenta Previa:** While it causes significant maternal bleeding, it rarely causes acute fetal blood loss unless there is placental abruption or trauma. The blood lost is primarily maternal. * **Battledore Placenta:** This refers to the insertion of the umbilical cord at the margin of the placenta. It is usually an incidental finding and does not typically cause acute fetal anemia or sinusoidal patterns. * **Succenturiate Placenta:** This is an accessory lobe of the placenta. While it increases the risk of vasa previa (if vessels run between lobes), the condition itself does not cause a sinusoidal pattern unless those vessels rupture. **High-Yield Clinical Pearls for NEET-PG:** * **Apt Test:** Used to differentiate fetal blood from maternal blood in cases of vaginal bleeding (positive in vasa previa). * **Causes of Sinusoidal Pattern:** Fetal anemia (Rh isoimmunization, Parvovirus B19, vasa previa), severe hypoxia, and certain drugs (e.g., narcotics like alphaprodine). * **Management:** A persistent sinusoidal pattern requires immediate Cesarean delivery.

Q: Which of the following is NOT a sonographic finding of fetal syphilis?

Lymphadenopathy. **Explanation:** Congenital syphilis is caused by the transplacental transmission of *Treponema pallidum*. The sonographic findings of fetal syphilis are primarily a reflection of fetal inflammatory response, severe anemia, and hepatic dysfunction. **Why Lymphadenopathy is the correct answer:** While lymphadenopathy is a classic physical exam finding in **neonates** with early congenital syphilis (presenting as generalized swelling or "snuffles"), it is **not** a detectable or characteristic finding on **prenatal ultrasound**. Fetal sonography focuses on organomegaly and fluid distribution rather than discrete fetal lymph node visualization. **Analysis of Incorrect Options:** * **Hepatomegaly (Option A):** This is the **most common** and often the earliest sonographic sign of fetal syphilis. It results from direct treponemal infiltration of the liver and extramedullary hematopoiesis. * **Placentomegaly (Option C):** A thick, enlarged placenta (typically >4-5 cm in the second/third trimester) is a hallmark of syphilis. It occurs due to villous edema and inflammation (villitis). * **Ascites/Hydrops (Option D):** As the disease progresses, hepatic dysfunction (leading to hypoalbuminemia) and severe anemia lead to fetal hydrops, characterized by ascites, pleural effusion, and skin edema. **NEET-PG High-Yield Pearls:** * **Triad of Fetal Syphilis:** Hepatomegaly, Placentomegaly, and Polyhydramnios. * **Screening:** All pregnant women should be screened at the first prenatal visit with non-treponemal tests (VDRL/RPR). * **Treatment of Choice:** Parenteral **Penicillin G** is the only treatment documented to be effective for preventing maternal transmission to the fetus and treating fetal infection. * **Jarisch-Herxheimer Reaction:** Pregnant women treated for syphilis must be monitored for this reaction, as it can precipitate preterm labor or fetal distress.

Q: Hyperemesis gravidarum is typically most severe at which gestational age?

9 weeks. **Explanation:** **Hyperemesis Gravidarum (HG)** is a severe form of nausea and vomiting in pregnancy characterized by weight loss, ketonuria, and electrolyte imbalances. The severity and timing of HG are directly correlated with the serum levels of **Human Chorionic Gonadotropin (hCG)**. 1. **Why 9 Weeks is Correct:** Serum hCG levels begin to rise shortly after implantation, doubling every 48–72 hours. These levels reach their **peak between 8 and 12 weeks** of gestation (averaging around 9–10 weeks). Because the pathogenesis of HG is linked to the high concentration of hCG (and its stimulatory effect on the TSH receptor), symptoms are most intense during this peak. 2. **Why Other Options are Incorrect:** * **6 Weeks:** This is typically when "morning sickness" begins (onset), but hCG levels have not yet reached their maximum concentration. * **28 and 36 Weeks:** These represent the third trimester. In most cases, HG resolves by 16–20 weeks as hCG levels plateau and decline. Persistent vomiting in late pregnancy should prompt investigation for other causes like HELLP syndrome, acute fatty liver of pregnancy, or gastrointestinal issues. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Multiple gestations and Molar pregnancies (due to excessively high hCG levels). * **Wernicke’s Encephalopathy:** A rare but serious complication of HG due to **Vitamin B1 (Thiamine)** deficiency. Always replenish Thiamine before giving IV Dextrose. * **Electrolyte Imbalance:** Most common pattern is **Hypokalemic Hypochloremic Metabolic Alkalosis**. * **First-line Pharmacotherapy:** Pyridoxine (Vitamin B6) ± Doxylamine.

Q: Which of the following congenital malformations will most predictably result in oligohydramnios?

Renal agenesis. ### Explanation The volume of amniotic fluid is a dynamic balance between production and removal. From the second trimester onwards, **fetal urine** becomes the primary source of amniotic fluid, while **fetal swallowing** is the primary route of removal. **Why Renal Agenesis is Correct:** In cases of **bilateral renal agenesis** (Potter’s Syndrome), there is a complete failure of fetal urine production. Since the primary source of amniotic fluid is absent, severe **oligohydramnios** (Amniotic Fluid Index < 5 cm) inevitably occurs. This lack of fluid leads to secondary complications like pulmonary hypoplasia and limb deformities due to uterine compression. **Why Other Options are Incorrect:** * **Anencephaly:** This condition typically results in **polyhydramnios**. The absence of the swallowing reflex (due to neural defects) and the transudation of fluid from the exposed meninges lead to an accumulation of fluid. * **Pyloric Stenosis:** While it involves a gastrointestinal obstruction, it occurs late or postnatally and does not significantly impair fetal swallowing in utero. Therefore, it is not a classic cause of polyhydramnios or oligohydramnios. * **Tracheoesophageal Fistula (TEF):** This often results in **polyhydramnios**. If the fistula prevents the fetus from effectively swallowing and absorbing amniotic fluid through the GI tract, the fluid accumulates in the gestational sac. **NEET-PG Clinical Pearls:** * **Potter’s Sequence:** Remember the mnemonic **POTTER** (Pulmonary hypoplasia, Oligohydramnios, Twisted face, Twisted skin, Extremity defects, Renal agenesis). * **Amniotic Fluid Index (AFI):** Normal range is 5–25 cm. 25 cm is polyhydramnios. * **Drug Link:** Maternal intake of **ACE inhibitors** or **NSAIDs** in the second/third trimester can also cause oligohydramnios by reducing fetal renal perfusion.

Q: Nausea and vomiting are common in pregnancy. Hyperemesis gravidarum is a serious and potentially fatal problem. Which of the following findings should alert the physician to the diagnosis of hyperemesis gravidarum early in its course?

Ketonuria. ### Explanation **Hyperemesis Gravidarum (HG)** is a severe form of nausea and vomiting in pregnancy characterized by persistent vomiting, weight loss (>5% of pre-pregnancy weight), and dehydration. **1. Why Ketonuria is the Correct Answer:** The hallmark of HG is a state of **starvation metabolism**. When a patient cannot retain oral intake, the body exhausts its glycogen stores and begins breaking down fats for energy. This process produces ketone bodies (acetone, acetoacetate, and beta-hydroxybutyrate), which are excreted in the urine. **Ketonuria** is the earliest objective laboratory finding that differentiates HG from simple morning sickness and indicates the need for hospitalization and IV fluid resuscitation. **2. Analysis of Incorrect Options:** * **A. ECG evidence of hypokalemia:** While hypokalemia occurs due to loss of gastric secretions and decreased intake, ECG changes (like U-waves or T-wave flattening) are **late signs** of severe electrolyte depletion, not early diagnostic markers. * **B. Metabolic acidosis:** HG typically causes **Metabolic Alkalosis** (due to loss of hydrochloric acid from the stomach). Metabolic acidosis only occurs in terminal stages due to starvation ketosis or renal failure, making it an incorrect early finding. * **C. Jaundice:** This is a **late and grave sign** indicating hepatic involvement (centrilobular necrosis). It is not used for early diagnosis. **3. NEET-PG High-Yield Pearls:** * **Most common electrolyte abnormality:** Hypokalemic hypochloremic metabolic alkalosis. * **Hormonal link:** Strongly associated with peak levels of **hCG** and Estrogen (often seen in molar pregnancies and multiple gestations). * **Wernicke’s Encephalopathy:** A dreaded complication caused by **Vitamin B1 (Thiamine) deficiency**; always supplement Thiamine before giving Dextrose-containing fluids. * **First-line Drug:** Pyridoxine (Vit B6) +/- Doxylamine.

Q: Diagnosis of Down syndrome at 11 weeks gestation can be assessed by:

Chorionic villous biopsy. **Explanation:** The diagnosis of Down syndrome (Trisomy 21) requires a **definitive genetic analysis** (karyotyping or FISH) to identify the extra chromosome 21. 1. **Why Chorionic Villous Biopsy (CVS) is correct:** CVS is an invasive diagnostic procedure performed between **10 and 13 weeks** of gestation. It involves taking a sample of placental tissue (chorionic villi), which shares the same genetic makeup as the fetus. Since the question specifies **11 weeks**, CVS is the gold-standard diagnostic tool available at this specific gestational age. 2. **Why other options are incorrect:** * **Ultrasonography:** While USG can detect "soft markers" like increased Nuchal Translucency (NT) at 11–13 weeks, it is a **screening tool**, not a diagnostic one. It suggests a risk but cannot confirm the diagnosis. * **Amniocentesis:** This is a definitive diagnostic test, but it is typically performed between **15 and 20 weeks**. Performing it before 15 weeks (early amniocentesis) is avoided due to higher risks of clubfoot (talipes) and pregnancy loss. * **Doppler Ultrasound:** This is used to assess blood flow in maternal and fetal vessels (e.g., Uterine or Umbilical artery) to monitor fetal well-being and growth restriction; it has no role in the primary diagnosis of chromosomal aneuploidies. **High-Yield Clinical Pearls for NEET-PG:** * **First Trimester Screening (Combined Test):** Includes NT scan + PAPP-A + β-hCG (performed between 11–13+6 weeks). * **Definitive Diagnosis:** CVS (10–13 weeks) or Amniocentesis (>15 weeks). * **NIPT (Non-Invasive Prenatal Testing):** Analyzes cell-free fetal DNA in maternal blood; it is the most sensitive screening test but still requires confirmation via CVS or Amniocentesis.

Question 1

Which of the following has proven to be effective in the management of preeclampsia?

Accepted Answer

Calcium

Answer

Zinc

Answer

Magnesium

Answer

None

Question 2

What is the effect of preeclampsia on the glomerular filtration rate?

Accepted Answer

Decreases

Answer

Increases

Answer

Remains the same

Answer

May increase or decrease

Question 3

Which of the following side-effects is NOT associated with the use of magnesium sulfate in pregnancy?

Accepted Answer

Bradycardia

Answer

Muscular paralysis

Answer

Cardiac arrhythmias

Answer

Respiratory depression

Question 4

A sinusoidal heart rate pattern is most commonly associated with which of the following conditions?

Accepted Answer

Vasa previa

Answer

Placenta previa

Answer

Battledore placenta

Answer

Succenturiate placenta

Question 5

Which of the following is NOT a sonographic finding of fetal syphilis?

Accepted Answer

Lymphadenopathy

Answer

Hepatomegaly

Answer

Placentomegaly

Answer

Ascites/hydrops

Question 6

Hyperemesis gravidarum is typically most severe at which gestational age?

Accepted Answer

9 weeks

Answer

6 weeks

Answer

28 weeks

Answer

36 weeks

Question 7

Which of the following congenital malformations will most predictably result in oligohydramnios?

Accepted Answer

Renal agenesis

Answer

Anencephaly

Answer

Pyloric stenosis

Answer

Tracheoesophageal fistula

Question 8

Highest transmission of hepatitis B from mother to fetus occurs if the mother is infected during which period?

Accepted Answer

3rd trimester

Answer

1st trimester

Answer

2nd trimester

Answer

At the time of implantation

Question 9

Nausea and vomiting are common in pregnancy. Hyperemesis gravidarum is a serious and potentially fatal problem. Which of the following findings should alert the physician to the diagnosis of hyperemesis gravidarum early in its course?

Accepted Answer

Ketonuria

Answer

Electrocardiographic evidence of hypokalemia

Answer

Metabolic acidosis

Answer

Jaundice

Question 10

Diagnosis of Down syndrome at 11 weeks gestation can be assessed by:

Accepted Answer

Chorionic villous biopsy

Answer

Ultrasonography

Answer

Aminocentesis

Answer

Doppler ultrasound

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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