Maternal-Fetal Medicine Practice Questions

Q: Which of the following is the most common predisposing factor for placenta accreta?

Placenta previa. **Explanation:** **Placenta accreta** occurs due to a defect in the **decidua basalis**, specifically the absence of the Nitabuch layer, which allows chorionic villi to invade the myometrium directly. **Why Placenta Previa is the correct answer:** While several factors can cause decidual deficiency, **placenta previa** is statistically the most significant predisposing factor. When the placenta implants in the lower uterine segment, the decidua is naturally thinner and less vascularized than in the upper segment, facilitating abnormal adherence. The risk is synergistically increased if a patient has both placenta previa and a previous uterine scar. **Analysis of Incorrect Options:** * **Previous Cesarean Section (C):** This is a major risk factor, but it is the *combination* of a previous C-section with a current placenta previa that poses the highest risk. In isolation, placenta previa remains the most common clinical association found in accreta cases. * **Recent Curettage (B) & Myomectomy (A):** These involve uterine trauma that can lead to localized decidual defects. While they are recognized risk factors, they are statistically less common causes of placenta accreta compared to the implantation site issues seen in placenta previa. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Correlation:** If a patient has placenta previa and 1 previous C-section, the risk of accreta is ~11%. With 4 or more C-sections and previa, the risk jumps to **>60%**. * **Management:** The gold standard management for confirmed placenta accreta is a **planned cesarean hysterectomy**. * **Diagnosis:** Antenatal diagnosis is primarily via **Color Doppler Ultrasound** (showing loss of retroplacental clear zone and bladder wall irregularities).

Q: Macrosomia is seen in all of the following conditions EXCEPT:

Hydrocephalus. **Explanation:** **Macrosomia** is defined as a birth weight >4000g or >4500g (regardless of gestational age) or a birth weight above the 90th percentile for gestational age. It refers to a generalized increase in body size and fat deposition. **Why Hydrocephalus is the Correct Answer:** Hydrocephalus involves an abnormal accumulation of cerebrospinal fluid (CSF) within the brain's ventricles, leading to an **enlarged head circumference (macrocephaly)**. While the head is disproportionately large, the overall body weight does not necessarily exceed the 90th percentile. Therefore, hydrocephalus causes macrocephaly, not true macrosomia. **Analysis of Incorrect Options:** * **Diabetes Mellitus:** Maternal hyperglycemia leads to fetal hyperglycemia, which stimulates the fetal pancreas to produce excess **insulin**. Since insulin is a potent anabolic hormone (fetal growth factor), it causes excessive deposition of fat and glycogen, leading to macrosomia. * **Obesity:** Maternal obesity is one of the most common risk factors for macrosomia due to increased nutrient availability and insulin resistance. * **Post-maturity:** Pregnancies exceeding 42 weeks allow for a longer period of intrauterine growth. If the placenta remains functional, the fetus continues to gain weight, often resulting in macrosomia. **High-Yield Clinical Pearls for NEET-PG:** * **Beckwith-Wiedemann Syndrome:** A classic high-yield cause of macrosomia characterized by the triad of macrosomia, macroglossia, and omphalocele. * **Infant of Diabetic Mother (IDM):** These infants are "large and plump" but have small brains (except for the heart and adrenals, most organs are enlarged). * **Complications:** Macrosomia increases the risk of shoulder dystocia, Erb’s palsy, and neonatal hypoglycemia.

Q: On Doppler studies, which finding is an ominous sign for an Intrauterine Growth Restriction (IUGR) fetus?

Reverse diastolic flow. **Explanation:** In the management of Intrauterine Growth Restriction (IUGR), Umbilical Artery (UA) Doppler is the gold standard for monitoring fetal well-being and placental resistance. **1. Why Reverse Diastolic Flow (REDF) is the correct answer:** As placental insufficiency worsens, the resistance in the umbilical artery increases. Initially, this leads to a decrease in end-diastolic flow. When more than 70% of the placental vascular bed is obliterated, the flow during diastole stops (Absent End Diastolic Velocity - AEDV). The most critical and **ominous** stage is **Reversed End Diastolic Velocity (REDF)**, where blood actually flows back toward the fetus during diastole. This indicates imminent fetal compromise, severe hypoxia, and acidosis, usually necessitating immediate delivery. **2. Why other options are incorrect:** * **A. Increased S/D ratio:** This is an early sign of increased placental resistance. While abnormal, it is not "ominous" as it precedes AEDV and REDV. * **B. Diastolic notch:** A notch in the **Uterine Artery** waveform (not Umbilical) at 20–24 weeks is a screening marker for the *risk* of developing pre-eclampsia or IUGR, but it is not a sign of acute fetal jeopardy. **Clinical Pearls for NEET-PG:** * **Sequence of Doppler changes:** Increased S/D ratio → AEDV → REDV → Abnormal Ductus Venosus (DV) flow (a-wave reversal). * **Ductus Venosus:** Reversal of the 'a-wave' in the DV is the most specific predictor of fetal death within 48–72 hours. * **Brain Sparing Effect:** Identified by a *decrease* in the Pulsatility Index (PI) of the Middle Cerebral Artery (MCA), indicating blood shunting to the fetal brain.

Q: A 32-year-old woman, 6 weeks pregnant, with a history of a previous child diagnosed with beta-thalassemia, is concerned about the current pregnancy. Which of the following methods is most likely to establish an accurate prenatal diagnosis for beta-thalassemia?

Chorionic villus sampling. **Explanation:** **1. Why Chorionic Villus Sampling (CVS) is correct:** Beta-thalassemia is a monogenic (single-gene) disorder caused by mutations in the HBB gene. To establish a definitive prenatal diagnosis, **fetal DNA analysis** is required. CVS is the preferred method in this scenario because it can be performed early in pregnancy (**10–13 weeks**). It involves obtaining trophoblastic tissue, which provides sufficient fetal DNA for PCR-based mutation analysis or linkage studies. Early diagnosis allows for safer options regarding pregnancy management if the fetus is affected. **2. Why other options are incorrect:** * **A. Fetal ultrasound:** While ultrasound is vital for structural screening (e.g., nuchal translucency), it cannot detect single-gene mutations like beta-thalassemia, which does not typically present with gross anatomical defects in the first trimester. * **B. Cord blood electrophoresis:** This requires Cordocentesis (Percutaneous Umbilical Blood Sampling), which is usually performed after **18 weeks**. While it can diagnose hemoglobinopathies, it is performed much later than CVS and carries a higher risk of fetal loss. * **D. Buccal mucosal cytology:** This may help determine the carrier status of the parents, but it cannot diagnose the genetic status of the current fetus. **Clinical Pearls for NEET-PG:** * **Gold Standard for DNA diagnosis:** CVS (10–13 weeks) or Amniocentesis (15–20 weeks). * **Thalassemia Screening:** The **Naked Eye Single Tube Red Cell Osmotic Fragility Test (NESTROFT)** is a common screening tool, but **Hb Electrophoresis (HbA2 > 3.5%)** is the confirmatory test for carrier status. * **Preimplantation Genetic Diagnosis (PGD):** An alternative for future pregnancies to avoid termination by testing embryos created via IVF.

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.

Question 1

Which of the following is the most common predisposing factor for placenta accreta?

Accepted Answer

Placenta previa

Answer

Myomectomy

Answer

Recent curettage

Answer

Previous cesarean section

Question 2

For maturity estimation, amniotic fluid cells are stained with which of the following?

Accepted Answer

Nile blue sulphate

Answer

Methylene blue

Answer

Mucicarmine

Answer

Sudan black

Question 3

Macrosomia is seen in all of the following conditions EXCEPT:

Accepted Answer

Hydrocephalus

Answer

Diabetes mellitus

Answer

Obesity

Answer

Post maturity

Question 4

On Doppler studies, which finding is an ominous sign for an Intrauterine Growth Restriction (IUGR) fetus?

Accepted Answer

Reverse diastolic flow

Answer

Increased S/D ratio

Answer

Diastolic notch

Answer

All of the above

Question 5

A 32-year-old woman, 6 weeks pregnant, with a history of a previous child diagnosed with beta-thalassemia, is concerned about the current pregnancy. Which of the following methods is most likely to establish an accurate prenatal diagnosis for beta-thalassemia?

Accepted Answer

Chorionic villus sampling

Answer

Fetal ultrasound at 12 weeks

Answer

Cord blood electrophoresis

Answer

Buccal mucosal cytology of both parents

Question 6

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 7

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 8

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 9

What is the best method to prevent cardiac failure in a pregnant woman with severe mitral stenosis, who is likely to experience failure during the antenatal period?

Accepted Answer

Balloon mitral valvuloplasty in the second trimester

Answer

Furosemide throughout pregnancy

Answer

Digoxin for all patients

Answer

Admission at 30 weeks gestation

Question 10

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

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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