Maternal-Fetal Medicine Practice Questions

Q: Ultrasound is useful in a diabetic mother in all the following except one?

Confirm fetal maturity. **Explanation:** In diabetic pregnancies, ultrasound is a vital tool for monitoring, but it is **not reliable for confirming fetal maturity**, particularly lung maturity. 1. **Why Option A is correct:** In diabetic mothers, there is a significant **dissociation between fetal size and functional maturity**. Due to maternal hyperglycemia, the fetus often experiences accelerated growth (macrosomia). An ultrasound may show a large fetus with advanced biometry, but the fetal lungs may still be immature. Hyperinsulinemia in the fetus inhibits the production of surfactant by type II pneumocytes. Therefore, fetal maturity must be confirmed via gestational age dating or amniocentesis (L/S ratio), not ultrasound parameters. 2. **Why the other options are incorrect:** * **Detect fetal malformation (B):** Diabetic mothers have a higher risk of congenital anomalies (e.g., Cardiac defects, Neural Tube Defects, Caudal Regression Syndrome). Targeted USG (Level II scan) is the gold standard for screening. * **Detect hydramnios (C):** Polyhydramnios is common in poorly controlled diabetes due to fetal osmotic diuresis (fetal polyuria). USG is used to measure the Amniotic Fluid Index (AFI). * **Diagnose hydrocephalus (D):** Hydrocephalus is one of the CNS malformations associated with pre-gestational diabetes and is easily diagnosed via ultrasound. **Clinical Pearls for NEET-PG:** * **Most common anomaly** in diabetic pregnancy: Cardiac defects (specifically VSD). * **Most specific anomaly:** Caudal Regression Syndrome (Sacral Agenesis). * **Best time for anomaly scan:** 18–20 weeks. * **Lecithin/Sphingomyelin (L/S) ratio:** In diabetic mothers, a ratio of >2.0 may still be associated with Respiratory Distress Syndrome (RDS); hence, the presence of **Phosphatidylglycerol (PG)** is a more reliable indicator of lung maturity.

Q: Oral anticoagulants given to pregnant women can cause which of the following fetal malformations?

Craniofacial malformation. **Explanation:** Oral anticoagulants, specifically **Warfarin** (a vitamin K antagonist), are known teratogens when administered during the first trimester (specifically between 6–9 weeks of gestation). This leads to a constellation of defects known as **Fetal Warfarin Syndrome (Warfarin Embryopathy).** **1. Why Craniofacial Malformation is Correct:** Warfarin crosses the placenta and interferes with the γ-carboxylation of proteins like osteocalcin, which are essential for bone and cartilage formation. The hallmark of this syndrome is **midfacial hypoplasia** (depressed nasal bridge) and **choanal atresia**. These are classic craniofacial malformations. Another pathognomonic feature is **stippled epiphyses** (chondrodysplasia punctata), primarily affecting the axial skeleton. **2. Why Other Options are Incorrect:** * **Long bones limb defect:** While Warfarin affects bone mineralization, it typically causes stippling of the epiphyses rather than gross limb reduction defects (which are more characteristic of Thalidomide). * **Cardiovascular malformation:** These are more commonly associated with Lithium (Ebstein’s anomaly) or poorly controlled maternal diabetes, rather than oral anticoagulants. * **Costochondral dysplasia:** While Warfarin affects cartilage, "costochondral dysplasia" is not a standard term used to describe the specific stippling seen in Warfarin embryopathy. **NEET-PG High-Yield Pearls:** * **Safe Alternative:** Low Molecular Weight Heparin (LMWH) or Unfractionated Heparin (UFH) are the drugs of choice in pregnancy as they **do not cross the placenta.** * **Critical Period:** Exposure between **6–9 weeks** is most critical for embryopathy. * **Late Pregnancy Risks:** Use in the second/third trimester can lead to fetal CNS hemorrhage and ophthalmic defects (microphthalmia, optic atrophy). * **Breastfeeding:** Warfarin is safe during breastfeeding as it is not excreted in breast milk.

Q: A 30-year-old obese woman with diabetes mellitus presents at 19 weeks' gestation. She notes recent lack of adherence to her diabetic regimen but is now motivated to improve. Her ophthalmologic examination and ECG are normal. Urinalysis is negative for proteinuria. Laboratory studies show: Hemoglobin A1c: 10.8%; Glucose: 222 mg/dL; TSH: 1.0 mIU/mL; Free T4: 1.7 ng/dL; Creatinine: 1.1 mg/dL. In which of the following conditions is the risk of development the same in diabetics as in the general population?

Congenital adrenal hyperplasia. **Explanation:** The core concept tested here is the specific spectrum of maternal and fetal complications associated with pre-gestational diabetes mellitus (PGDM). **Why Option C is Correct:** **Congenital Adrenal Hyperplasia (CAH)** is an autosomal recessive genetic disorder involving enzyme deficiencies (most commonly 21-hydroxylase) in the steroidogenesis pathway. Its occurrence is determined at conception by parental genotype and is **not influenced by the maternal metabolic environment** or glycemic control. Therefore, the risk remains the same as in the general population. **Why Other Options are Incorrect:** * **A. Asymptomatic Bacteriuria (ASB):** Pregnant women with diabetes have a significantly higher prevalence of ASB due to glucosuria (which promotes bacterial growth) and autonomic bladder dysfunction. If untreated, they have a higher risk of progression to pyelonephritis. * **B. Preeclampsia:** Diabetes is a major risk factor for preeclampsia. The risk is further increased in patients with high HbA1c, obesity, or underlying vasculopathy (White’s Classification R/F). * **D. Postpartum Hemorrhage (PPH):** Diabetics are at increased risk for PPH due to two main factors: **Uterine atony** (caused by overdistension from fetal macrosomia or polyhydramnios) and an increased rate of **instrumental/cesarean deliveries**. **High-Yield NEET-PG Pearls:** * **HbA1c & Malformations:** An HbA1c >10% (as seen in this patient) is associated with a >20% risk of congenital anomalies. * **Most Common Anomaly:** Cardiac defects (specifically Ventricular Septal Defect). * **Most Specific Anomaly:** Caudal Regression Syndrome (Sacral Agenesis). * **Target HbA1c:** Ideally <6.5% pre-conception to minimize the risk of structural anomalies (which occur during organogenesis in the first trimester).

Q: Which of the following is NOT true about gestational diabetes mellitus complicating pregnancy?

Brain enlargement as a part of macrosomia. **Explanation:** In Gestational Diabetes Mellitus (GDM), maternal hyperglycemia leads to fetal hyperglycemia, which stimulates the fetal pancreas to secrete excess insulin. Insulin acts as a potent growth hormone in utero, leading to **macrosomia**. However, this growth is **asymmetric**. While there is organomegaly of the liver, heart, and adrenals, and increased subcutaneous fat, the **brain is characteristically spared** and does not enlarge. Therefore, brain enlargement is NOT a feature of diabetic macrosomia. **Analysis of other options:** * **Hyperglycemia in the infant (Option B):** This is a tricky distractor. While the neonate typically experiences *hypoglycemia* after birth (due to persistent hyperinsulinism once the glucose supply is cut), the fetus itself is **hyperglycemic** in utero as glucose crosses the placenta freely. (Note: In many clinical contexts, "infant" refers to the newborn, making this a common point of confusion; however, in the context of GDM complications, brain sparing is the definitive "false" statement). * **First-trimester abortion (Option C):** Poorly controlled pre-gestational diabetes is a known risk factor for spontaneous abortion and congenital anomalies (like Sacral Agenesis). * **Unexplained fetal death (Option D):** Stillbirths, often occurring after 36 weeks, are a classic complication of uncontrolled GDM, thought to be due to fetal acidosis or hyperglycemia-induced hypoxia. **High-Yield Pearls for NEET-PG:** * **Macrosomia Definition:** Birth weight >4000g or >4500g. * **Pedersen Hypothesis:** Maternal hyperglycemia → Fetal hyperglycemia → Fetal hyperinsulinemia → Macrosomia. * **Most common anomaly:** Cardiac anomalies (specifically VSD/TGA). * **Most specific anomaly:** Caudal Regression Syndrome (Sacral Agenesis). * **Neonatal Metabolic Complications:** Hypoglycemia, Hypocalcemia, Hypomagnesemia, and Hyperbilirubinemia.

Q: A 20-year-old married woman with a history of congenital heart disease presents for pre-conceptional counseling. Which of the following is the most likely adverse event she might face during pregnancy?

Arrhythmia. **Explanation:** In women with congenital heart disease (CHD), **arrhythmias** are the most common cardiovascular complication encountered during pregnancy. This is primarily due to the physiological changes of pregnancy—such as increased plasma volume, elevated heart rate, and increased sympathetic activity—which act as triggers for underlying arrhythmogenic substrates (e.g., surgical scars from previous repairs or dilated cardiac chambers). Atrial arrhythmias, particularly supraventricular tachycardia (SVT), are the most frequent manifestations. **Analysis of Options:** * **A. Heart Failure:** While a significant cause of morbidity and the leading cause of maternal death in cardiac patients, it occurs less frequently than arrhythmias in the overall population of women with CHD. * **B. Thromboembolism:** Pregnancy is a hypercoagulable state, and the risk is elevated in patients with cyanotic heart disease or mechanical valves; however, it is not the *most likely* event compared to rhythm disturbances. * **C. Hemorrhage:** While obstetric hemorrhage is a general risk, it is not a specific "cardiac" adverse event directly resulting from the pathophysiology of CHD. * **D. Arrhythmia (Correct):** Multiple prospective studies (like CARPREG and ZAHARA) have consistently identified arrhythmias as the most prevalent complication in pregnant women with CHD. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cardiac complication in pregnancy:** Arrhythmia. * **Most common cause of maternal death in heart disease:** Heart Failure (specifically in the peripartum period). * **Highest risk period:** The immediate postpartum period (first 24–48 hours) due to the sudden "autotransfusion" of blood from the involuting uterus and relief of IVC compression. * **CARPREG Risk Score:** Key predictors of adverse events include prior cardiac events (TIA/stroke/arrhythmia), NYHA Class >II, left-sided obstruction, and ejection fraction <40%.

Q: Which is the smallest fetal diameter?

Bitemporal. To answer this question, it is essential to distinguish between the **transverse** and **anteroposterior** diameters of the fetal skull. ### **1. Why Bitemporal is Correct** The **Bitemporal diameter (8.0 cm)** is the distance between the furthest points of the coronal sutures. It is the **smallest transverse diameter** of the fetal skull. In clinical practice, this diameter is significant because it is smaller than the biparietal diameter, allowing the head to navigate the pelvic brim more easily during the initial stages of engagement. ### **2. Analysis of Incorrect Options** * **Biparietal (9.5 cm):** This is the distance between the two parietal eminences. While it is the most commonly measured transverse diameter in ultrasonography, it is 1.5 cm larger than the bitemporal diameter. * **Submentobregmatic (9.5 cm):** This is an anteroposterior diameter extending from the junction of the floor of the mouth and neck to the center of the bregma. It is the presenting diameter in **Face presentations** when the head is completely extended. * **Occipitofrontal (11.5 cm):** This diameter extends from the occipital protuberance to the root of the nose (glabella). it is the presenting diameter in a **deflexed vertex** (occipito-posterior) presentation. ### **3. High-Yield Clinical Pearls for NEET-PG** * **Smallest Anteroposterior Diameter:** Suboccipitobregmatic (9.5 cm) – the presenting diameter in a well-flexed vertex presentation. * **Largest Anteroposterior Diameter:** Mento-vertical (13.5 cm) – seen in **Brow presentations**, making vaginal delivery usually impossible. * **Largest Transverse Diameter:** Biparietal (9.5 cm). * **Super-subparietal (8.5 cm):** A transverse diameter measured from a point below one parietal eminence to a point above the other; relevant in cases of asynclitism.

Q: A primigravida in the 2nd trimester tested positive for toxoplasmosis. Vertical transmission of toxoplasmosis MOST commonly occurs in which trimester?

3rd trimester. The risk of vertical transmission in congenital toxoplasmosis follows a specific inverse relationship between the **rate of transmission** and the **severity of fetal damage**. ### Why the 3rd Trimester is Correct The risk of vertical transmission **increases as gestational age progresses**. It is highest in the **3rd trimester (60–80%)** due to increased placental blood flow and a thinner placental barrier, which facilitates the passage of *Toxoplasma gondii* tachyzoites from the mother to the fetus. ### Why Other Options are Incorrect * **1st Trimester:** While the risk of transmission is lowest here (approx. 10–15%), the **severity** of fetal involvement is highest, often leading to miscarriage or severe neurological damage. * **2nd Trimester:** The transmission rate is intermediate (approx. 25–30%). * **During Delivery:** Unlike HIV or Herpes, Toxoplasmosis is primarily a transplacental infection occurring *in utero*, not typically an intrapartum event. ### High-Yield Clinical Pearls for NEET-PG * **The Classic Triad (Sabin’s Triad):** Chorioretinitis (most common), Hydrocephalus, and Intracranial calcifications (diffuse). * **Diagnosis:** Maternal screening is done via IgM/IgG. Fetal diagnosis is best confirmed via **PCR of Amniotic Fluid** (Gold Standard). * **Treatment:** * If maternal infection is suspected but fetal infection is not confirmed: **Spiramycin** (prevents transmission). * If fetal infection is confirmed: **Pyrimethamine, Sulfadiazine, and Folinic acid**. * **Key Rule:** Transmission risk is **highest** in the 3rd trimester; Severity is **highest** in the 1st trimester.

Question 1

Ultrasound is useful in a diabetic mother in all the following except one?

Accepted Answer

Confirm fetal maturity

Answer

Detect fetal malformation

Answer

Detect hydramnios

Answer

Diagnose hydrocephalus

Question 2

Oral anticoagulants given to pregnant women can cause which of the following fetal malformations?

Accepted Answer

Craniofacial malformation

Answer

Long bones limb defect

Answer

Cardiovascular malformation

Answer

Costochondral dysplasia

Question 3

A 30-year-old obese woman with diabetes mellitus presents at 19 weeks' gestation. She notes recent lack of adherence to her diabetic regimen but is now motivated to improve. Her ophthalmologic examination and ECG are normal. Urinalysis is negative for proteinuria. Laboratory studies show: Hemoglobin A1c: 10.8%; Glucose: 222 mg/dL; TSH: 1.0 mIU/mL; Free T4: 1.7 ng/dL; Creatinine: 1.1 mg/dL. In which of the following conditions is the risk of development the same in diabetics as in the general population?

Accepted Answer

Congenital adrenal hyperplasia

Answer

Asymptomatic bacteriuria

Answer

Preeclampsia

Answer

Postpartum hemorrhage after delivery

Question 4

Which of the following is NOT true about gestational diabetes mellitus complicating pregnancy?

Accepted Answer

Brain enlargement as a part of macrosomia

Answer

Hyperglycemia in the infant

Answer

First-trimester abortion

Answer

Unexplained fetal death

Question 5

A 20-year-old married woman with a history of congenital heart disease presents for pre-conceptional counseling. Which of the following is the most likely adverse event she might face during pregnancy?

Accepted Answer

Arrhythmia

Answer

Heart Failure

Answer

Thromboembolism

Answer

Hemorrhage

Question 6

Which is the smallest fetal diameter?

Accepted Answer

Bitemporal

Answer

Biparietal

Answer

Submentobregmatic

Answer

Occipitofrontal

Question 7

A patient at 17 weeks gestation is diagnosed with intrauterine fetal demise on ultrasound. She presents 5 weeks after the scan without expelling the fetus, reporting occasional spotting. What is the primary risk for this patient?

Accepted Answer

Consumptive coagulopathy with hypofibrinogenemia

Answer

Septic abortion

Answer

Recurrent abortions in the future

Answer

Rupture uterus

Question 8

A primigravida in the 2nd trimester tested positive for toxoplasmosis. Vertical transmission of toxoplasmosis MOST commonly occurs in which trimester?

Accepted Answer

3rd trimester

Answer

1st trimester

Answer

2nd trimester

Answer

During delivery

Question 9

Which of the following statements regarding listeriosis in pregnancy is FALSE?

Accepted Answer

The primary mode of transmission of Listeria monocytogenes is not sexual.

Answer

Listeriosis in pregnancy is associated with meningoencephalitis of the newborn.

Answer

Listeriosis may present with a skin rash.

Answer

In cases of listeriosis during pregnancy, amniotic fluid may be meconium stained.

Question 10

In which of the following clinical scenarios is Anti-D prophylaxis not recommended?

Accepted Answer

Spontaneous miscarriage at 14 weeks in a sensitized RhD-negative woman

Answer

Therapeutic termination of pregnancy by medical method in a 10-week non-sensitized RhD-negative woman

Answer

Medically managed ectopic pregnancy at 8 weeks in a non-sensitized RhD-negative woman

Answer

Threatened miscarriage in a 13-week non-sensitized RhD-negative woman

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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