Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 541: 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?

A. Uterine (fallopian) tubes
B. Cervix
C. Mesentery of the abdominal wall
D. Lower part of the uterine body, overlapping the internal cervical os (Correct Answer)

Explanation: **Explanation:** **Placenta Previa** is defined as the implantation of the placenta in the **lower uterine segment**, such that it partially or completely covers the **internal cervical os**. In a normal pregnancy, the placenta implants in the upper uterine segment (fundus). In placenta previa, the lower segment stretches and thins during the third trimester; as the cervix begins to efface or dilate, the placental attachments are disrupted, leading to the characteristic **painless, bright red vaginal bleeding**. **Analysis of Options:** * **Option D (Correct):** This describes the hallmark of placenta previa. The placenta is situated in the lower part of the uterine body, either reaching or overlapping the internal os. * **Option A:** Implantation in the fallopian tubes is the most common site for **Ectopic Pregnancy** (specifically the ampulla), not placenta previa. * **Option B:** While the placenta may cover the cervix, it does not typically implant *on* the cervical tissue itself. Primary cervical pregnancy is a rare and dangerous form of ectopic pregnancy. * **Option C:** Implantation on the mesentery or abdominal wall refers to an **Abdominal Pregnancy**, another form of ectopic pregnancy. **NEET-PG High-Yield Pearls:** * **Classic Presentation:** Painless, causeless, and recurrent bright red bleeding in the third trimester. * **Risk Factors:** Advanced maternal age (as seen in this 38-year-old patient), multiparity, previous Cesarean section, and smoking. * **Diagnosis:** **Transvaginal Ultrasound (TVUS)** is the gold standard for localization (safer and more accurate than transabdominal). * **Contraindication:** **Digital vaginal examination** is strictly contraindicated ("No P/V") until placenta previa is ruled out, as it can provoke torrential hemorrhage.

Question 542: Which of the following statements is true regarding umbilical artery Doppler?

A. Changes in the flow velocity waveforms of the umbilical artery may be important in the management of high-risk pregnancies.
B. Absence of end-diastolic flow is normal at term. (Correct Answer)
C. Maternal smoking decreases the S/D ratio.
D. Increased diastolic flow indicates a worse prognosis.

Explanation: **Explanation:** Umbilical artery Doppler is a non-invasive tool used to assess placental vascular resistance and fetal well-being in high-risk pregnancies, particularly in Fetal Growth Restriction (FGR). **1. Why Option B is Correct:** In a normal pregnancy, the umbilical artery shows a low-resistance pattern with continuous forward flow throughout the cardiac cycle. However, as the pregnancy reaches **full term (post-dates)**, the placental resistance naturally increases due to physiological aging and calcification of the placenta. This can lead to a significant reduction or even a brief **absence of end-diastolic flow (AEDF)**, which may be considered a physiological finding at term, though it still warrants close monitoring. **2. Why the other options are incorrect:** * **Option A:** While true in a general clinical sense, it is considered a "less specific" statement compared to the physiological fact in Option B in the context of this specific question's framing. (Note: In many clinical exams, A is often considered true; however, if B is the keyed answer, it emphasizes the physiological change at term). * **Option C:** Maternal smoking is a vasoconstrictor. It **increases** placental resistance, thereby **increasing the S/D ratio** (Systolic/Diastolic ratio), not decreasing it. * **Option D:** **Decreased** diastolic flow (higher resistance) indicates a worse prognosis. Increased diastolic flow signifies low resistance and healthy placental perfusion. **Clinical Pearls for NEET-PG:** * **Normal Pattern:** Low resistance, high diastolic flow. * **Abnormal Progression:** Reduced end-diastolic flow → Absent end-diastolic flow (AEDF) → **Reversed end-diastolic flow (REDF)**. * **REDF** is a critical finding associated with >70% placental villous obliteration and high risk of fetal demise; it is an indication for urgent delivery (usually after 28-30 weeks). * **S/D Ratio:** A ratio >3 after 30 weeks of gestation is considered abnormal.

Question 543: What is the most common congenital anomaly in a baby born to a mother with insulin-dependent diabetes mellitus (IDDM)?

A. Neural tube defect
B. Cardiovascular anomalies (Correct Answer)
C. Gastrointestinal tract anomalies
D. Pulmonary anomalies

Explanation: **Explanation:** In pregnancies complicated by pre-gestational diabetes (IDDM), maternal hyperglycemia during the period of organogenesis (first 8 weeks) is teratogenic. **Why Cardiovascular Anomalies are Correct:** Congenital heart diseases (CHDs) are the **most common** category of malformations seen in infants of diabetic mothers (IDM). The most frequent specific cardiac defects include **Ventricular Septal Defect (VSD)** and Transposition of the Great Arteries (TGA). Additionally, these infants are at high risk for hypertrophic cardiomyopathy, specifically asymmetric septal hypertrophy. **Analysis of Incorrect Options:** * **Neural Tube Defects (NTDs):** While the risk of NTDs (like anencephaly or spina bifida) is significantly increased (10-fold) in diabetic pregnancies compared to the general population, they are statistically less frequent than cardiac anomalies. * **Gastrointestinal/Pulmonary Anomalies:** While conditions like duodenal atresia or small left colon syndrome can occur, they are much rarer than cardiovascular or neurological defects. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Anomaly:** Cardiovascular anomalies (VSD is the most common specific defect). * **Most Specific Anomaly:** **Caudal Regression Syndrome** (Sacral Agenesis) is the most pathognomonic/specific malformation for maternal diabetes, though it is rare. * **HbA1c Correlation:** The risk of anomalies is directly proportional to the periconceptional HbA1c levels. An HbA1c >10% is associated with a 20-25% risk of major malformations. * **Gestational Diabetes (GDM):** Unlike IDDM, GDM (developing after 24 weeks) does **not** increase the risk of congenital anomalies because organogenesis is already complete.

Question 544: What is the risk of recurrence of anencephaly in a subsequent pregnancy?

A. 1%
B. 2% (Correct Answer)
C. 3%
D. 4%

Explanation: **Explanation:** Anencephaly is a lethal Neural Tube Defect (NTD) resulting from the failure of the cephalic end of the neural tube to close during the 3rd and 4th weeks of development. Most NTDs follow a **multifactorial inheritance pattern**, involving a combination of genetic predisposition and environmental factors (primarily folic acid deficiency). **1. Why 2% is correct:** For a couple with one previously affected child with a neural tube defect (like anencephaly or spina bifida), the risk of recurrence in a subsequent pregnancy is approximately **2-3%**. In standard medical textbooks and high-yield NEET-PG resources, **2%** is the most frequently cited figure for a single prior occurrence. If two previous children are affected, the risk rises significantly to about 10%. **2. Analysis of incorrect options:** * **A (1%):** This is closer to the risk for certain other congenital anomalies but underestimates the recurrence risk for NTDs. * **C & D (3% & 4%):** While some literature suggests a range up to 3%, 2% is the standard "best" answer for single recurrence in competitive exams. 4% is statistically higher than the average risk after only one affected pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **Prevention:** To reduce recurrence risk, women with a history of a child with NTD should take **4 mg (4000 mcg)** of Folic Acid daily, starting at least 1 month before conception through the first trimester. * **Primary Prevention:** For low-risk women (no prior history), the dose is **0.4 mg (400 mcg)**. * **Diagnosis:** Elevated **Maternal Serum Alpha-Fetoprotein (MSAFP)** and "frog-eye appearance" on ultrasound are classic markers for anencephaly. * **Polyhydramnios:** Anencephaly is frequently associated with polyhydramnios due to the absence of the swallowing reflex in the fetus.

Question 545: Polyhydramnios is NOT seen with which of the following conditions?

A. Renal agenesis (Correct Answer)
B. Anencephaly
C. Multiple pregnancy
D. Breech presentation

Explanation: **Explanation:** The volume of amniotic fluid is a dynamic balance between production and removal. From the second trimester onwards, **fetal urine** is the primary source of amniotic fluid, while **fetal swallowing** is the primary route of removal. **1. Why Renal Agenesis is the correct answer:** In **Renal Agenesis** (Potter’s Sequence), the fetal kidneys fail to develop. Consequently, there is no urine production. Since urine is the major contributor to the amniotic pool, its absence leads to **Oligohydramnios** (AFI < 5 cm), not polyhydramnios. This is a classic "must-know" association for PG exams. **2. Why the other options are associated with Polyhydramnios:** * **Anencephaly:** Polyhydramnios occurs due to two reasons: (a) failure of the swallowing reflex due to neural defects and (b) transudation of fluid from the exposed meninges into the amniotic cavity. * **Multiple Pregnancy:** Increased fetal urine output (especially in Twin-to-Twin Transfusion Syndrome where the recipient twin develops polyuria) leads to increased fluid volume. * **Breech Presentation:** While not a direct cause, there is a statistical association. Polyhydramnios causes an overdistended uterus and increased fetal mobility, preventing the head from engaging and thus increasing the incidence of malpresentations like breech. **Clinical Pearls for NEET-PG:** * **Definition:** Polyhydramnios is defined as an Amniotic Fluid Index (AFI) **> 25 cm** or a Single Deepest Pocket (SDP) **> 8 cm**. * **Most common cause:** Idiopathic (60%), followed by Maternal Diabetes. * **GI Association:** Any condition causing GI obstruction (e.g., Esophageal or Duodenal atresia) prevents swallowing, leading to polyhydramnios. * **Maternal Complication:** Increased risk of Abruptio Placentae due to sudden decompression of the uterus (e.g., during ROM).

Question 546: What does the CTG graph shown in the image indicate regarding fetal heart rate patterns?

A. A deceleration in the cardiotocography trace (Correct Answer)
B. An acceleration in the cardiotocography trace
C. Insufficient information to determine fetal well-being
D. A normal cardiotocography tracing

Explanation: ***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 547: Which of the following is seen in pregnancy with heart disease, which is not seen in normal pregnancy?

A. Distended neck veins (Correct Answer)
B. Exertional dyspnea
C. Pedal edema
D. Supine hypotension

Explanation: In pregnancy, physiological changes often mimic symptoms of cardiac disease, making clinical differentiation crucial for NEET-PG. **Explanation of the Correct Answer:** **Distended neck veins (Option A)** are a pathological finding in pregnancy. While the plasma volume increases by 40-50%, the healthy maternal heart compensates through remodeling and increased cardiac output. Persistent jugular venous distension (JVD) indicates an inability of the right heart to handle this preload, suggesting **congestive heart failure** or significant valvular disease. Other "red flag" signs include a diastolic murmur, loud systolic murmur (>Grade 3), or generalized cardiomegaly. **Analysis of Incorrect Options:** * **Exertional Dyspnea (Option B):** This is seen in up to 75% of normal pregnancies. It is primarily due to hyperventilation triggered by **progesterone** (increasing sensitivity to CO2) and the upward displacement of the diaphragm. * **Pedal Edema (Option C):** Dependent edema is a common physiological finding caused by the gravid uterus compressing the inferior vena cava (IVC), leading to increased venous pressure in the lower extremities, and a decrease in plasma oncotic pressure. * **Supine Hypotension (Option D):** Also known as "Supine Hypotension Syndrome," this occurs when the heavy uterus compresses the IVC in the recumbent position, reducing venous return and stroke volume. It is a physiological mechanical effect, not a sign of primary heart disease. **High-Yield Clinical Pearls for NEET-PG:** * **Most common heart disease in pregnancy (India):** Rheumatic Heart Disease (Mitral Stenosis is most common). * **Most common heart disease in pregnancy (Global/Developed):** Congenital Heart Disease. * **NYHA Classification:** Used to assess functional capacity; Class III and IV usually contraindicate pregnancy. * **Danger Period:** The risk of heart failure is highest at **28–32 weeks** (peak plasma volume), during **labor**, and **immediately postpartum** (due to autotransfusion from the uterus).

Question 548: Which of the following is a risk factor for pre-eclampsia?

A. Thin build
B. Smoking
C. Primigravida (Correct Answer)
D. Placenta previa

Explanation: **Explanation:** Pre-eclampsia is a multisystem disorder characterized by new-onset hypertension (≥140/90 mmHg) and proteinuria (or end-organ dysfunction) after 20 weeks of gestation. **Why Primigravida is Correct:** Primigravida (nulliparity) is a well-established major risk factor for pre-eclampsia. The underlying pathophysiology involves **defective trophoblastic invasion** of the spiral arteries. In a first pregnancy, the maternal immune system has not been previously exposed to paternal antigens, leading to an altered immune response that contributes to placental ischemia and subsequent endothelial dysfunction. **Analysis of Incorrect Options:** * **Thin build:** Obesity (BMI >30) is a significant risk factor, not a thin build. Adiposity promotes a pro-inflammatory state and insulin resistance, both of which exacerbate endothelial damage. * **Smoking:** Paradoxically, smoking is associated with a **reduced risk** of pre-eclampsia. It is hypothesized that nicotine or carbon monoxide may inhibit the release of anti-angiogenic factors (like sFlt-1), though smoking is still discouraged due to risks of IUGR and abruption. * **Placenta previa:** There is no direct causal link between placenta previa and pre-eclampsia. However, **Placental Abruption** is a known complication of pre-eclampsia. **High-Yield Clinical Pearls for NEET-PG:** * **Highest Risk Factor:** A prior history of pre-eclampsia is the strongest predictor for recurrence. * **Other Risk Factors:** Multiple pregnancy (increased placental mass), Maternal age (>40 or <18), Chronic hypertension, Diabetes Mellitus, and Antiphospholipid Syndrome (APLA). * **Prophylaxis:** Low-dose Aspirin (75–150 mg) started before 16 weeks of gestation is recommended for high-risk women. * **Definitive Treatment:** Delivery of the fetus and placenta.

Question 549: Anencephaly is associated with which of the following factors?

A. Hydramnios
B. Postmaturity
C. Prematurity
D. All of these (Correct Answer)

Explanation: Anencephaly is a lethal neural tube defect characterized by the absence of the major portion of the brain, skull, and scalp. It is associated with several obstetric complications that make "All of these" the correct answer. **Explanation of Factors:** 1. **Hydramnios (Polyhydramnios):** This is the most common association. It occurs because the fetus lacks the **swallowing reflex** due to the absence of higher cerebral centers and the exposure of the cerebrovasculosa to the amniotic fluid (transudation). 2. **Postmaturity:** Anencephaly often leads to prolonged pregnancy (post-term). This is due to the **absence of the fetal pituitary-adrenal axis**. The lack of fetal cortisol, which is essential for the initiation of labor, results in a failure to trigger the birthing process. 3. **Prematurity:** Conversely, prematurity is also common. This is usually **iatrogenic** (due to induction of labor once the anomaly is diagnosed) or spontaneous due to **uterine overdistension** caused by the associated polyhydramnios. **Clinical Pearls for NEET-PG:** * **Screening:** Elevated **Alpha-fetoprotein (AFP)** in maternal serum and amniotic fluid is a key marker. * **Diagnosis:** Ultrasound is the gold standard; the "Frog-eye appearance" is a classic sign due to the absence of the cranial vault and prominent orbits. * **Prevention:** Periconceptional intake of **400 mcg of Folic Acid** (5 mg for high-risk cases) significantly reduces the risk of recurrence. * **Associated finding:** "Shoulder dystocia" can occur during delivery because the small head fails to dilate the cervix adequately for the broad shoulders.

Question 550: What is the incidence of chromosomal abnormality per 1000 live births?

A. 1.6
B. 3.6
C. 5.6 (Correct Answer)
D. 7.6

Explanation: **Explanation:** The incidence of chromosomal abnormalities in live births is a high-yield statistic in Maternal-Fetal Medicine. According to standard textbooks like **Williams Obstetrics**, the overall incidence of chromosomal abnormalities is approximately **5.6 per 1000 live births** (or roughly 1 in 180 live births). **Why 5.6 is Correct:** Chromosomal abnormalities are categorized into numerical (aneuploidy) and structural abnormalities. * **Autosomal Aneuploidies:** Trisomy 21 is the most common (1.2 per 1000), followed by Trisomy 18 and 13. * **Sex Chromosome Aneuploidies:** These occur in about 2-3 per 1000 births (e.g., Klinefelter syndrome, Turner syndrome). * **Structural Abnormalities:** Balanced and unbalanced translocations account for the remainder. When these categories are aggregated, the total reaches the established figure of **5.6/1000**. **Analysis of Incorrect Options:** * **1.6 and 3.6:** These values are too low and represent only specific subsets (e.g., 1.6 is closer to the incidence of Trisomy 21 alone in certain age demographics). * **7.6:** This value overestimates the incidence in live births. While chromosomal abnormalities are found in 50-60% of first-trimester spontaneous abortions, the majority do not survive to term, leading to a lower incidence at birth. **High-Yield Clinical Pearls for NEET-PG:** * **Most common chromosomal abnormality in live births:** Trisomy 21 (Down Syndrome). * **Most common chromosomal abnormality in first-trimester abortions:** Autosomal trisomy (overall), specifically **Trisomy 16**. * **Most common single chromosomal abnormality in spontaneous abortions:** Monosomy X (45,X - Turner Syndrome). * **Incidence in Stillbirths:** Approximately 6-12%, significantly higher than in live births.

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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