Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 351: The maternal side of the mature placenta is covered by which structure?

A. Amnion (Correct Answer)
B. Chorion
C. Decidua
D. Amniotic membrane

Explanation: **Explanation:** The mature placenta has two distinct surfaces: the **fetal surface** and the **maternal surface**. While the maternal surface (the side attached to the uterine wall) is anatomically composed of 15–20 lobes called cotyledons and is covered by the **decidua basalis**, the question asks about the structure that covers the placenta as a whole in the context of the fetal membranes. **Why Amnion is Correct:** In a mature placenta, the **amnion** is the innermost fetal membrane. At the end of pregnancy, the amnion and chorion fuse, but the amnion remains the most superficial layer. Crucially, the amnion reflects off the umbilical cord and covers the entire fetal surface. However, it also extends to cover the **maternal side** of the membranes (the periphery) and the placental margin. In the context of standard obstetric teaching (and specific exam patterns like NEET-PG), the amnion is identified as the definitive epithelial covering of the mature placental structure. **Analysis of Incorrect Options:** * **B. Chorion:** The chorion is the outer membrane. While it forms the bulk of the placenta (chorion frondosum), it lies deep to the amnion on the fetal side and is integrated into the placental plate. * **C. Decidua:** The decidua is the modified endometrium of pregnancy. While the *decidua basalis* forms the maternal base of the placenta, it is considered a maternal component rather than a "covering membrane" of the mature placental organ itself. * **D. Amniotic membrane:** This is a synonymous term for the amnion, but "Amnion" is the preferred anatomical nomenclature in standard textbooks like Williams Obstetrics or Dutta’s DC. **High-Yield Clinical Pearls for NEET-PG:** * **Fetal Surface:** Smooth, glistening, and covered by amnion. The umbilical cord is usually attached here (eccentric or central). * **Maternal Surface:** Rough, dull red, divided into cotyledons, and covered by a thin layer of **decidua basalis**. * **Schultze Mechanism:** Placenta is expelled with the fetal surface (amnion) presenting first (80% of cases). * **Matthews Duncan Mechanism:** Placenta is expelled with the maternal surface (cotyledons) presenting first.

Question 352: All are complications of hyperemesis gravidarum, EXCEPT?

A. Mallory-Weiss tears
B. Wernicke's encephalopathy
C. Renal failure
D. Hiatus hernia (Correct Answer)

Explanation: **Explanation:** Hyperemesis Gravidarum (HG) is a severe form of nausea and vomiting in pregnancy characterized by dehydration, electrolyte imbalance, and weight loss. **Why Hiatus Hernia is the Correct Answer:** A **Hiatus Hernia** is a structural anatomical defect where the stomach protrudes through the esophageal hiatus of the diaphragm. While HG involves forceful vomiting that increases intra-abdominal pressure, it does not *cause* a hiatus hernia. Conversely, a pre-existing hiatus hernia may actually be a predisposing factor or a differential diagnosis for severe vomiting, but it is not a complication resulting from HG. **Analysis of Incorrect Options (Complications of HG):** * **Mallory-Weiss Tears:** Forceful, repeated vomiting causes longitudinal mucosal lacerations at the gastroesophageal junction, leading to hematemesis. * **Wernicke’s Encephalopathy:** This is a critical complication caused by **Thiamine (Vitamin B1) deficiency** due to prolonged vomiting. It presents with the classic triad of ataxia, ophthalmoplegia, and confusion. * **Renal Failure:** Severe dehydration and hypovolemia lead to decreased renal perfusion, resulting in **Prerenal Azotemia** and potentially acute kidney injury. **High-Yield Clinical Pearls for NEET-PG:** * **Electrolyte Imbalance:** The most common pattern is **Hypokalemic Hypochloremic Metabolic Alkalosis**. * **Korsakoff Psychosis:** If Wernicke’s is left untreated, it can progress to irreversible memory loss and confabulation. * **Management Tip:** Always supplement **Thiamine before administering Dextrose** fluids in HG patients to prevent precipitating Wernicke’s encephalopathy. * **Other Complications:** Central Pontine Myelinolysis (due to rapid sodium correction), Boerhaave syndrome (esophageal rupture), and Vitamin K deficiency (coagulopathy).

Question 353: Which of the following indicates the most severe form of fetal distress?

A. Decreased S/D ratio
B. Reversal of diastolic flow (Correct Answer)
C. Absent diastolic flow
D. Increased S/D ratio

Explanation: This question assesses the interpretation of **Umbilical Artery Doppler**, a critical tool for monitoring fetal well-being in cases of Intrauterine Growth Restriction (IUGR) and placental insufficiency. ### **Explanation of the Correct Answer** The Umbilical Artery Doppler measures the resistance to blood flow from the fetus to the placenta. In a healthy pregnancy, resistance is low, ensuring continuous forward flow during diastole. As placental resistance increases (due to placental bed infarction or obliterative vasculopathy), the diastolic flow progressively decreases. **Reversal of End-Diastolic Flow (REDF)** is the most severe stage. It signifies that during diastole, blood actually flows backward from the placenta toward the fetal heart because the placental pressure exceeds the fetal systemic pressure. This indicates that over 70% of the placental villous vascular bed is obliterated. REDF is a critical warning sign of imminent fetal demise and usually necessitates immediate delivery (if the fetus is viable). ### **Analysis of Incorrect Options** * **Absent End-Diastolic Flow (AEDF):** This is a severe finding indicating roughly 60-70% placental damage. While critical, it is the stage *preceding* reversal; therefore, it is less severe than REDF. * **Increased S/D Ratio:** The Systolic/Diastolic ratio increases as resistance rises. While this indicates placental insufficiency, it is an early sign and far less ominous than the total loss or reversal of flow. * **Decreased S/D Ratio:** This is a normal physiological finding as pregnancy progresses, reflecting a healthy, low-resistance placental circuit. ### **NEET-PG High-Yield Pearls** * **Sequence of Deterioration:** Increased S/D Ratio → Absent End-Diastolic Flow (AEDF) → Reversed End-Diastolic Flow (REDF). * **Ductus Venosus:** If REDF is noted, the next step is often checking the Ductus Venosus; an **absent or reversed 'a' wave** in the Ductus Venosus is the most definitive sign of impending fetal heart failure. * **Management:** REDF at >32 weeks usually warrants immediate Cesarean section. Between 28-32 weeks, management is individualized based on steroid administration and daily monitoring.

Question 354: All of the following are true about anencephaly except?

A. Facial presentation
B. Increased alpha-fetoprotein
C. Enlarged adrenal gland (Correct Answer)
D. Polyhydramnios

Explanation: ### Explanation **Anencephaly** is a lethal neural tube defect characterized by the absence of the cranial vault and cerebral hemispheres. **Why Option C is the Correct Answer (The "Except"):** In anencephaly, there is a failure of development of the hypothalamus and the pituitary gland. This leads to a lack of **Adrenocorticotropic Hormone (ACTH)** secretion. Since the fetal adrenal cortex (specifically the fetal zone) depends on ACTH for growth, the **adrenal glands are characteristically hypoplastic (atrophied)**, not enlarged. **Analysis of Other Options:** * **A. Face Presentation:** Due to the absence of the bony vault (calvarium), the head cannot engage normally. The face becomes the leading part, making face presentation a common clinical finding. * **B. Increased Alpha-Fetoprotein (AFP):** Anencephaly is an "open" neural tube defect. This allows AFP to leak from the fetal circulation into the amniotic fluid and subsequently into the maternal serum. Maternal Serum AFP (MSAFP) is a key screening tool. * **D. Polyhydramnios:** This occurs due to two reasons: 1) The fetus lacks the swallowing reflex due to neurological deficit, and 2) Transudation of fluid from the exposed meninges/choroid plexus. **High-Yield Clinical Pearls for NEET-PG:** * **Frog-like Appearance:** The characteristic facies due to prominent, bulging eyes. * **Shoulder Dystocia:** Common due to the large size of the trunk relative to the absent head. * **Post-term Pregnancy:** Often occurs because the lack of the fetal pituitary-adrenal axis delays the hormonal triggers for labor. * **Prevention:** 400 mcg of Folic acid daily (pre-conceptionally); 4 mg daily if there is a previous history of NTD. * **Diagnosis:** Best made via Ultrasound (10–14 weeks); "Mickey Mouse sign" in early scans.

Question 355: Which of the following is true in twin-reversed arterial perfusion (TRAP) sequence?

A. It is caused by a large arteriovenous placental shunt.
B. The donor twin is at risk of cardiomegaly and high output heart failure. (Correct Answer)
C. The most effective treatment is injection of potassium chloride into the recipient twin.
D. Placental arterial perfusion pressure in the recipient exceeds that of the donor.

Explanation: **Explanation:** **Twin-Reversed Arterial Perfusion (TRAP) sequence** is a rare, severe complication of monochorionic twin pregnancies. It occurs due to large **artery-to-artery (A-A)** and vein-to-vein (V-V) placental anastomoses. 1. **Why Option B is Correct:** In TRAP, the "pump twin" (donor) provides systemic circulation for both itself and the "acardiac twin" (recipient). This massive increase in cardiac workload leads to **volume overload**, resulting in cardiomegaly, polyhydramnios, and eventually **high-output heart failure** (hydrops fetalis) in the pump twin. 2. **Why Other Options are Incorrect:** * **Option A:** TRAP is primarily driven by large **arterio-arterial (A-A)** anastomoses, not arteriovenous (A-V) shunts (which are the hallmark of Twin-to-Twin Transfusion Syndrome). * **Option C:** Injection of KCl into the recipient is contraindicated. Because of the large vascular connections, the KCl can cross into the pump twin’s circulation, causing immediate cardiac arrest. The preferred treatment is **radiofrequency ablation (RFA)** or bipolar cord coagulation of the acardiac twin. * **Option D:** The **donor’s arterial pressure exceeds the recipient’s**. This pressure gradient forces deoxygenated blood "backward" into the umbilical artery of the recipient (hence "reversed perfusion"). **High-Yield Clinical Pearls for NEET-PG:** * **The Acardiac Twin:** Receives poorly oxygenated blood via its umbilical artery; this leads to "upper body regression" (absent head/heart/upper limbs). * **Diagnosis:** Confirmed by **Doppler ultrasound** showing retrograde (reversed) flow in the umbilical artery of the acardiac twin. * **Prognosis:** Without intervention, the mortality rate for the pump twin is approximately 50–70% due to heart failure or preterm birth.

Question 356: In which of the following conditions can normal pregnancy be continued?

A. Primary pulmonary hypertension
B. Wolf-Parkinson-White syndrome (Correct Answer)
C. Eisenmenger syndrome
D. Marfan syndrome with dilated aortic root

Explanation: **Explanation:** In obstetric medicine, cardiac conditions are categorized by risk. The correct answer is **Wolf-Parkinson-White (WPW) syndrome** because it is generally considered a low-risk condition that does not contraindicate pregnancy. **1. Why WPW Syndrome is the Correct Answer:** WPW syndrome is a pre-excitation syndrome involving an accessory pathway (Bundle of Kent). While pregnancy can increase the frequency of paroxysmal supraventricular tachycardia (PSVT) due to hemodynamic changes, the condition itself does not carry a high risk of maternal mortality. Most patients remain asymptomatic or can be managed safely with medical therapy (like Adenosine or Beta-blockers) or cardioversion if necessary. It is not an indication for termination of pregnancy. **2. Why the Other Options are Incorrect:** The other three options represent **WHO Class IV Cardiac Conditions**, which carry a maternal mortality risk of 25–50%. In these cases, pregnancy is medically contraindicated, and early termination is usually advised: * **Primary Pulmonary Hypertension (PPH):** High risk of sudden right heart failure and death, especially during labor and the immediate postpartum period. * **Eisenmenger Syndrome:** The reversal of a left-to-right shunt due to pulmonary hypertension leads to severe hypoxemia and heart failure. Mortality is extremely high (up to 50%). * **Marfan Syndrome with Dilated Aortic Root (>4 cm):** Pregnancy increases the risk of life-threatening aortic dissection or rupture due to hormonal effects on the vascular media and increased cardiac output. **NEET-PG High-Yield Pearls:** * **Absolute Contraindications to Pregnancy:** Eisenmenger syndrome, Pulmonary Hypertension (PPH), Marfan with aortic root >4cm, and Severe Mitral Stenosis/Aortic Stenosis. * **Most common heart disease in pregnancy:** Rheumatic Heart Disease (Mitral Stenosis is the most common lesion). * **Most common cause of maternal death in cardiac patients:** Heart failure (often during the 28th–32nd week or immediate postpartum).

Question 357: Oxytocin challenge test for assessing fetal well-being is contraindicated in all of the following except:

A. Placenta previa
B. Previous two lower segment Caesarean sections (LSCS)
C. Breech presentation (Correct Answer)
D. Premature labor

Explanation: The **Oxytocin Challenge Test (OCT)**, also known as the Contraction Stress Test (CST), evaluates the fetal heart rate response to uterine contractions. The goal is to identify uteroplacental insufficiency. Because the test involves inducing contractions, it is contraindicated in any condition where labor or strong uterine activity poses a risk to the mother or fetus. ### Why Breech Presentation is the Correct Answer **Breech presentation** is a **relative contraindication** for vaginal delivery, but it is **not a contraindication** for an OCT. Inducing mild contractions to assess fetal well-being does not inherently increase the risk of complications in a breech fetus, provided other contraindications (like placenta previa) are absent. If the OCT is reactive, the clinician can then decide on the mode of delivery. ### Explanation of Incorrect Options (Contraindications) * **Placenta Previa:** Contractions can cause cervical effacement and dilatation, leading to massive maternal hemorrhage from the low-lying placenta. * **Previous Two LSCS:** Multiple prior uterine scars increase the risk of **uterine rupture** during induced contractions. (Note: A single prior LSCS is a relative contraindication, but two or more are absolute). * **Premature Labor:** Inducing contractions in a patient at risk for preterm birth can trigger active labor, leading to the delivery of a premature infant. ### High-Yield Clinical Pearls for NEET-PG * **Mechanism:** A positive OCT (Abnormal) shows **late decelerations** following 50% or more of contractions, indicating fetal hypoxia. * **Prerequisites:** Requires at least 3 contractions in 10 minutes, each lasting 40–60 seconds. * **Absolute Contraindications:** Placenta previa, vasa previa, previous classical CS, and prior uterine rupture. * **Interpretation:** A **Negative** result (no late decelerations) is highly reassuring and predicts fetal survival for 1 week (High Negative Predictive Value).

Question 358: A 28-week pregnant patient presents with a blood pressure of 140/90 mm Hg during a prenatal visit. Urine analysis is performed to detect the presence of proteins. Which of the following is a risk factor for progressing to pre-eclampsia in this patient?

A. Family history of pre-eclampsia
B. Age
C. Hydatidiform mole
D. All of the above (Correct Answer)

Explanation: ### Explanation The correct answer is **D. All of the above**. 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. The pathogenesis involves abnormal placentation leading to endothelial dysfunction. Identifying risk factors is crucial for early screening and prophylaxis (e.g., low-dose Aspirin). **Why the options are correct:** * **Family History (Option A):** Pre-eclampsia has a strong genetic component. A woman with a family history (mother or sister) has a 2- to 4-fold increased risk of developing the condition. * **Age (Option B):** Maternal age is a significant risk factor. Both extremes of reproductive age—**nulliparous teenagers** (due to an immature immune response to paternal antigens) and **women >35–40 years** (due to underlying vascular aging)—are at higher risk. * **Hydatidiform Mole (Option C):** This is a classic high-yield association. Molar pregnancies involve excessive trophoblastic proliferation, leading to early-onset pre-eclampsia (often occurring **before 20 weeks**). **High-Yield Clinical Pearls for NEET-PG:** * **Strongest Risk Factor:** A prior history of pre-eclampsia is the strongest individual predictor for recurrence. * **Nulliparity:** Being a "primigravida" is a classic risk factor (often called the "disease of theories" or "disease of primigravida"). * **Other Risk Factors:** Obesity (BMI >30), Multiple pregnancy, Pre-existing medical conditions (Chronic HTN, Diabetes, SLE, Antiphospholipid syndrome), and IVF pregnancies. * **Prophylaxis:** Low-dose Aspirin (75–150 mg) is recommended starting from 12–16 weeks for high-risk patients.

Question 359: Which of the following is NOT a contraindication to pregnancy?

A. Severe pulmonary hypertension
B. Severe obstructive valvular lesions
C. Large secundum atrial septal defect with left to right shunt (Correct Answer)
D. Marfan syndrome with dilated aorta

Explanation: In maternal-fetal medicine, cardiac conditions are categorized by risk using the **Modified WHO (mWHO) Classification**. This question tests your ability to distinguish between conditions where pregnancy is contraindicated (mWHO Class IV) and those that are manageable. ### **Explanation of the Correct Answer** **C. Large secundum atrial septal defect (ASD) with left-to-right shunt:** Most uncomplicated left-to-right shunts (ASD, VSD, PDA) are well-tolerated during pregnancy. Even a large secundum ASD is generally classified as **mWHO Class II**, meaning there is only a small increased risk of maternal mortality. As long as pulmonary pressures remain normal, the physiological drop in systemic vascular resistance (SVR) during pregnancy does not significantly worsen the shunt. ### **Why the Other Options are Wrong (Contraindications)** These conditions fall under **mWHO Class IV**, where the risk of maternal mortality is extremely high (25–50%), and pregnancy is contraindicated: * **A. Severe Pulmonary Hypertension (including Eisenmenger Syndrome):** The fixed pulmonary resistance cannot accommodate the 50% increase in blood volume, leading to right heart failure or sudden death, especially postpartum. * **B. Severe Obstructive Valvular Lesions:** Specifically **Severe Mitral Stenosis** and **Severe Aortic Stenosis**. These patients cannot increase cardiac output to meet pregnancy demands, leading to acute pulmonary edema. * **D. Marfan Syndrome with Dilated Aorta:** If the aortic root is **>40 mm**, there is a high risk of aortic dissection or rupture due to the hyperdynamic state and hormonal changes (estrogen/progesterone) affecting the vessel wall. ### **High-Yield NEET-PG Pearls** * **Most common heart disease in pregnancy:** Mitral Stenosis (Rheumatic). * **Most common congenital heart disease in pregnancy:** ASD. * **Highest risk period:** The immediate postpartum period (due to "autotransfusion" from the contracting uterus). * **Absolute Contraindications (mWHO IV):** Pulmonary HTN, LVEF <30%, previous Peripartum Cardiomyopathy with residual dysfunction, Severe MS/AS, and Aortic dilation >45mm (Bicuspid) or >40mm (Marfan).

Question 360: When does the first trimester of pregnancy complete?

A. 12 completed weeks
B. 13 completed weeks
C. 14 completed weeks (Correct Answer)
D. 16 completed weeks

Explanation: **Explanation:** The division of pregnancy into trimesters is a clinical convention used to monitor fetal development and maternal changes. According to the standard obstetric definitions followed by major international bodies (such as ACOG and WHO) and standard textbooks like **Williams Obstetrics**, the first trimester extends from the first day of the last menstrual period (LMP) through **13 weeks and 6 days**. Therefore, the first trimester is considered over once **14 completed weeks** have begun. **Analysis of Options:** * **14 completed weeks (Correct):** This marks the transition into the second trimester (14–27 weeks). In clinical practice and exams, the first trimester is defined as 0–13+6 weeks; thus, completion occurs at the 14-week mark. * **12 completed weeks (Incorrect):** While many older texts and lay resources use 12 weeks as a milestone (as the uterus becomes an abdominal organ and the risk of miscarriage drops), it is not the formal obstetric definition for the end of the first trimester. * **13 completed weeks (Incorrect):** This is a common distractor. While the 13th week is the final week of the trimester, the trimester is not "complete" until the end of that week (13 weeks 6 days). * **16 completed weeks (Incorrect):** This is well into the second trimester and does not correspond to any major trimester transition. **High-Yield Clinical Pearls for NEET-PG:** * **Trimester Divisions:** * 1st Trimester: 0 to 13+6 weeks. * 2nd Trimester: 14 to 27+6 weeks. * 3rd Trimester: 28 weeks until delivery. * **NT Scan Timing:** The Nuchal Translucency (NT) scan, a crucial first-trimester screening, must be performed between **11 and 13+6 weeks**. * **Uterine Position:** The uterus remains a pelvic organ until **12 weeks**, after which it becomes palpable per abdomen.

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

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free