Maternal-Fetal Medicine — MCQs
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Which ultrasound measurement is a marker of fetal growth restriction?
A patient with a history of previous unexplained intrauterine fetal death at term now presents at 9 months of gestation with itching, a bilirubin level of 3 mg/dL, and mildly elevated AST. A diagnosis of intrahepatic cholestasis of pregnancy (IHCP) was made. What is the appropriate management?
A 28-year-old pregnant woman at 26 weeks gestation presents with a 3-day history of increasing shortness of breath. Her past medical history includes well-controlled bronchial asthma. On examination, she is tachypneic and uncomfortable, with a pulse of 110 bpm, respirations of 32/min, and blood pressure of 160/90 mm Hg. Cardiac exam reveals a regular heart rhythm without gallop and a grade 2/6 systolic murmur in the pulmonic area. Lung auscultation is clear. Abdominal examination confirms a 26-week gravid uterus. Laboratory data includes Hb 12 g/dL, Hct 36%, WBC 7.0/uL, BUN 23 mg/dL, creatinine 0.9 mg/dL, sodium 136 mEq/L, and potassium 4.2 mEq/L. Arterial blood gases on room air show pH 7.34, PCO2 34 mm Hg, and PO2 68 mm Hg. Peak expiratory flow rate (PEFR) is 450 L/min. Chest x-rays are available. What is the most likely diagnosis?
A pregnant woman at 12 weeks gestation is exposed to chickenpox and has no prior history of the disease. What is the best management if she is found to be seronegative for varicella-zoster virus antibodies?
What is a blighted ovum?
What is the earliest sign of magnesium toxicity?
A patient at 22 weeks gestation is diagnosed with IUD which occurred at 17 weeks but did not have a miscarriage. This patient is at increased risk for which of the following?
Recurrent abortion in the first trimester is most often due to what cause?
Which one of the following causes the greatest risk of ectopic pregnancy?
A woman presents with amenorrhea of 2 months duration, lower abdominal pain, facial pallor, fainting, and shock. What is the most likely diagnosis?
Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs
Question 511: Which ultrasound measurement is a marker of fetal growth restriction?
- A. Abdominal Circumference (AC) (Correct Answer)
- B. Amniotic Fluid Index (AFI)
- C. Femur Length (FL)
- D. Biparietal Diameter (BPD)
Explanation: **Explanation:** The **Abdominal Circumference (AC)** is the most sensitive single biometric parameter for diagnosing Fetal Growth Restriction (FGR). This is because the fetal liver is the first organ to be affected by nutritional deprivation. In growth-restricted fetuses, glycogen stores in the liver are depleted, and subcutaneous fat in the abdomen is reduced. Since the AC measurement primarily reflects the size of the liver and the amount of abdominal fat, it decreases significantly before other parameters, making it the hallmark of asymmetrical FGR. **Analysis of Incorrect Options:** * **B. Amniotic Fluid Index (AFI):** While oligohydramnios (low AFI) is a common *consequence* of placental insufficiency in FGR due to reduced fetal renal perfusion, it is a marker of fetal well-being and placental function rather than a direct biometric measurement of growth. * **C. Femur Length (FL):** This measures long bone growth. In asymmetrical FGR (the most common type), the body "spares" the brain and skeleton; therefore, the FL often remains within normal limits while the AC lags behind. * **D. Biparietal Diameter (BPD):** This measures head size. Due to the "brain-sparing effect," the head circumference and BPD are usually preserved until the late stages of growth restriction. **High-Yield Clinical Pearls for NEET-PG:** * **Estimated Fetal Weight (EFW):** The most accurate diagnosis of FGR is an EFW <10th percentile for gestational age, which is calculated using a combination of AC, BPD, and FL (Hadlock’s formula). * **AC <10th percentile:** This is the single best predictor of a small-for-gestational-age (SGA) neonate. * **Ponderal Index:** Used to differentiate between symmetrical and asymmetrical FGR. * **Doppler Studies:** Umbilical artery Doppler is the gold standard for monitoring the *health* of a growth-restricted fetus, but AC remains the primary *growth* marker.
Question 512: A patient with a history of previous unexplained intrauterine fetal death at term now presents at 9 months of gestation with itching, a bilirubin level of 3 mg/dL, and mildly elevated AST. A diagnosis of intrahepatic cholestasis of pregnancy (IHCP) was made. What is the appropriate management?
- A. Elective Cesarean section at 36 weeks
- B. Ursodeoxycholic acid with induction of labor at 38 weeks and strict intrapartum fetal monitoring (Correct Answer)
- C. Symptomatic management and delivery at 40+ weeks
- D. Fresh frozen plasma transfusion
Explanation: **Explanation:** **Intrahepatic Cholestasis of Pregnancy (IHCP)** is a metabolic disorder of the liver characterized by pruritus (typically on palms and soles) and elevated serum bile acids/bilirubin. The primary concern in IHCP is the increased risk of **sudden intrauterine fetal death (IUFD)**, likely due to bile acid-induced fetal arrhythmias or vasospasm of placental vessels. 1. **Why Option B is Correct:** * **Medical Management:** **Ursodeoxycholic acid (UDCA)** is the drug of choice. It improves maternal symptoms (itching) and biochemical markers by enhancing bile flow. * **Timing of Delivery:** Because the risk of IUFD increases significantly after 37–38 weeks, current guidelines (RCOG/ACOG) recommend induction of labor between **37 and 38 weeks** to prevent late-term stillbirth. * **Monitoring:** Strict intrapartum fetal monitoring is essential as these fetuses have a higher incidence of meconium-stained liquor and fetal distress. 2. **Why Other Options are Incorrect:** * **Option A:** Elective Cesarean section is not routinely indicated for IHCP. Induction of labor is preferred unless there are obstetric contraindications. 36 weeks is generally too early unless bile acids are severely elevated (>100 µmol/L). * **Option C:** Waiting until 40+ weeks is dangerous. The risk of unexplained IUFD in IHCP rises sharply as the pregnancy reaches post-term. * **Option D:** FFP is used for coagulopathy (e.g., AFLP). While IHCP can cause Vitamin K malabsorption, FFP is not the primary treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Hallmark Symptom:** Pruritus without a rash, worse at night, starting on palms and soles. * **Gold Standard Investigation:** Elevated **Serum Bile Acids** (>10 µmol/L). * **Drug of Choice:** Ursodeoxycholic acid (UDCA). * **Recurrence:** High risk of recurrence (60–90%) in subsequent pregnancies. * **Key Association:** Increased risk of preterm labor and meconium-stained amniotic fluid.
Question 513: A 28-year-old pregnant woman at 26 weeks gestation presents with a 3-day history of increasing shortness of breath. Her past medical history includes well-controlled bronchial asthma. On examination, she is tachypneic and uncomfortable, with a pulse of 110 bpm, respirations of 32/min, and blood pressure of 160/90 mm Hg. Cardiac exam reveals a regular heart rhythm without gallop and a grade 2/6 systolic murmur in the pulmonic area. Lung auscultation is clear. Abdominal examination confirms a 26-week gravid uterus. Laboratory data includes Hb 12 g/dL, Hct 36%, WBC 7.0/uL, BUN 23 mg/dL, creatinine 0.9 mg/dL, sodium 136 mEq/L, and potassium 4.2 mEq/L. Arterial blood gases on room air show pH 7.34, PCO2 34 mm Hg, and PO2 68 mm Hg. Peak expiratory flow rate (PEFR) is 450 L/min. Chest x-rays are available. What is the most likely diagnosis?
- A. Acute anxiety
- B. Pulmonary embolism (Correct Answer)
- C. Acute exacerbation of bronchial asthma
- D. High-output heart failure
Explanation: ### Explanation The correct diagnosis is **Pulmonary Embolism (PE)**. Pregnancy is a hypercoagulable state, increasing the risk of venous thromboembolism (VTE) five-fold. **Why Pulmonary Embolism is correct:** The patient presents with sudden-onset tachypnea, tachycardia, and significant hypoxemia ($PO_2$ of 68 mm Hg). A crucial finding here is the **Arterial Blood Gas (ABG)**. In pregnancy, the normal physiological state is a mild respiratory alkalosis (due to progesterone-driven hyperventilation), with a typical $PCO_2$ of 27–32 mm Hg and a pH of 7.40–7.45. A $PCO_2$ of 34 mm Hg and pH of 7.34 in this patient indicates **respiratory acidosis**, signaling respiratory failure and an inability to compensate, which is highly suggestive of a major PE. **Why incorrect options are wrong:** * **Acute Anxiety:** While it causes tachypnea, it would result in respiratory alkalosis (low $PCO_2$, high pH) and would not cause significant hypoxemia ($PO_2$ 68). * **Acute Exacerbation of Bronchial Asthma:** The **Peak Expiratory Flow Rate (PEFR)** of 450 L/min is normal, and lung auscultation is clear (no wheezing), effectively ruling out an asthma attack. * **High-output Heart Failure:** While common in pregnancy, the clear lung fields and absence of a gallop rhythm make this unlikely. The systolic murmur (grade 2/6) is a common physiological finding in pregnancy due to increased blood volume. **High-Yield Clinical Pearls for NEET-PG:** * **ABG in Pregnancy:** Normal $pH$ 7.44, $PCO_2$ ~30 mmHg, $PO_2$ >100 mmHg. A "normal" non-pregnant $PCO_2$ (40 mmHg) in a pregnant woman signifies impending respiratory failure. * **Diagnosis:** The gold standard for PE in pregnancy is **CT Pulmonary Angiography (CTPA)** or V/Q scan. * **Treatment:** Low Molecular Weight Heparin (LMWH) is the drug of choice; Warfarin is contraindicated due to teratogenicity.
Question 514: A pregnant woman at 12 weeks gestation is exposed to chickenpox and has no prior history of the disease. What is the best management if she is found to be seronegative for varicella-zoster virus antibodies?
- A. Administer varicella-zoster vaccine as soon as possible after exposure.
- B. Administer varicella-zoster immunoglobulin as soon as possible after exposure. (Correct Answer)
- C. Termination of pregnancy.
- D. Treatment with oral acyclovir if infection occurs.
Explanation: ### Explanation **Correct Option: B (Administer varicella-zoster immunoglobulin)** The primary goal in a seronegative pregnant woman exposed to chickenpox is to prevent maternal infection and subsequent complications (like varicella pneumonia). **Varicella-Zoster Immunoglobulin (VZIG)** provides passive immunization and is the treatment of choice for post-exposure prophylaxis in non-immune pregnant women. It should ideally be administered within **96 hours** (up to 10 days) of exposure to be most effective. **Analysis of Incorrect Options:** * **Option A:** The varicella vaccine is a **live-attenuated vaccine** and is strictly contraindicated during pregnancy due to the theoretical risk of fetal infection. * **Option C:** Termination is not indicated. While Congenital Varicella Syndrome (CVS) is a risk (highest between 13–20 weeks), the overall incidence is low (approx. 1–2%). Management focuses on monitoring via serial ultrasounds. * **Option D:** Oral acyclovir is used for **treatment** once clinical symptoms appear, not for primary prophylaxis in an asymptomatic exposed patient. **High-Yield Clinical Pearls for NEET-PG:** * **Congenital Varicella Syndrome:** Characterized by cicatricial skin scarring, limb hypoplasia, chorioretinitis, and microcephaly. * **Timing Risk:** The risk of CVS is highest if maternal infection occurs between **13 and 20 weeks**. * **Neonatal Varicella:** If the mother develops a rash **5 days before to 2 days after delivery**, the neonate is at high risk for severe disseminated varicella and must receive VZIG immediately at birth. * **Vaccination:** Women should be advised to avoid pregnancy for **1 month** after receiving the varicella vaccine.
Question 515: What is a blighted ovum?
- A. Synaptic knobs
- B. Avascular villi (Correct Answer)
- C. Intervillous hemorrhage
- D. None of the above
Explanation: ### Explanation A **blighted ovum**, also known as an **anembryonic pregnancy**, occurs when a fertilized egg attaches to the uterine wall, but the embryo fails to develop or resorbs after development has started. **1. Why "Avascular Villi" is Correct:** In a blighted ovum, the gestational sac and trophoblastic tissue continue to grow for a period, but because there is no functioning embryo, there is no established fetal circulation. Histologically, this manifests as **avascular villi** (chorionic villi lacking fetal blood vessels). These villi often undergo hydropic degeneration (swelling), though not to the extent seen in a molar pregnancy. The absence of fetal vessels is the hallmark pathological finding. **2. Analysis of Incorrect Options:** * **Option A (Synaptic knobs):** This is a distractor. Synaptic knobs are anatomical structures found at the ends of axons in the nervous system, unrelated to placental pathology. * **Option C (Intervillous hemorrhage):** While hemorrhage can occur during any miscarriage (spontaneous abortion), it is a non-specific finding. It refers to bleeding between the villi and is not the defining histological characteristic of a blighted ovum. **3. NEET-PG High-Yield Pearls:** * **Diagnosis:** On ultrasound, a blighted ovum is diagnosed when the **Mean Sac Diameter (MSD) is ≥25 mm** without a visible embryo (transvaginal scan). * **Commonest Cause:** Chromosomal abnormalities, most frequently **Autosomal Trisomies** (Trisomy 16 being the most common). * **Clinical Presentation:** The patient may have symptoms of early pregnancy (positive HCG), followed by minor spotting or a routine ultrasound showing an empty sac. * **Management:** Options include expectant management, medical evacuation (Misoprostol), or surgical evacuation (MVA/D&C).
Question 516: What is the earliest sign of magnesium toxicity?
- A. Falling oxygen saturation on pulse oximetry (Correct Answer)
- B. Respiratory depression
- C. Cardiac arrest
- D. Anuria
Explanation: **Explanation:** Magnesium sulfate ($MgSO_4$) is the drug of choice for seizure prophylaxis in pre-eclampsia and control in eclampsia. However, it has a narrow therapeutic index (4–7 mEq/L). **Why Option A is Correct:** Traditionally, the loss of deep tendon reflexes (patellar reflex) was taught as the first clinical sign of toxicity. However, recent clinical evidence and updated protocols highlight that **falling oxygen saturation ($SpO_2 < 95\%$)** on pulse oximetry is the **earliest objective indicator** of magnesium toxicity. This occurs due to the weakening of respiratory muscles and minor changes in alveolar ventilation that precede a visible drop in respiratory rate. **Analysis of Incorrect Options:** * **B. Respiratory Depression:** This occurs at higher serum levels (12–15 mEq/L). While it is a classic sign, it follows the loss of reflexes and the initial drop in $SpO_2$. * **C. Cardiac Arrest:** This is a late and terminal sign of toxicity, typically occurring when serum levels exceed 25 mEq/L. * **D. Anuria:** Magnesium is excreted solely by the kidneys. While oliguria/anuria is a **predisposing factor** that leads to toxicity (due to accumulation), it is not a sign of the toxicity itself. **High-Yield Clinical Pearls for NEET-PG:** * **Order of Toxicity:** $SpO_2$ drop → Loss of Patellar Reflex (8–10 mEq/L) → Respiratory Depression (12–15 mEq/L) → Cardiac Arrest (>25 mEq/L). * **Monitoring:** Always check urine output (>30 ml/hr), respiratory rate (>12/min), and presence of knee jerk before every dose. * **Antidote:** 10 ml of 10% **Calcium Gluconate** administered IV over 10 minutes.
Question 517: A patient at 22 weeks gestation is diagnosed with IUD which occurred at 17 weeks but did not have a miscarriage. This patient is at increased risk for which of the following?
- A. Septic abortion
- B. Recurrent abortion
- C. Consumptive coagulopathy with hypofibrinogenemia (Correct Answer)
- D. Future infertility
Explanation: **Explanation:** The correct answer is **C. Consumptive coagulopathy with hypofibrinogenemia.** This clinical scenario describes a **Missed Abortion** (or intrauterine fetal death) that has been retained for a prolonged period (5 weeks). When a dead fetus is retained in the uterus for more than 4 weeks, there is a significant risk of **Disseminated Intravascular Coagulation (DIC)**. **Pathophysiology:** The underlying mechanism involves the gradual release of **thromboplastin** (tissue factor) from the degenerating fetal tissues and placenta into the maternal circulation. This triggers the extrinsic coagulation pathway, leading to the consumption of clotting factors—most notably **fibrinogen**—and platelets. This results in hypofibrinogenemia (levels <150 mg/dL) and a systemic bleeding diathesis. **Analysis of Incorrect Options:** * **A. Septic abortion:** While a missed abortion can become infected, it is not the primary systemic risk associated specifically with the *prolonged retention* of a sterile intrauterine death. * **B. Recurrent abortion:** This refers to three or more consecutive pregnancy losses. A single episode of missed abortion does not inherently categorize the patient as having recurrent loss unless a specific genetic or anatomical cause is identified. * **D. Future infertility:** A missed abortion, if managed correctly without complications like severe Asherman syndrome or chronic PID, does not typically lead to infertility. **High-Yield NEET-PG Pearls:** * **The "4-Week Rule":** The risk of DIC in missed abortion becomes clinically significant after **4 weeks** of retention. * **Initial Investigation:** In a suspected missed abortion, the first investigation is an **Ultrasound** to confirm the absence of fetal heart activity. * **Coagulation Profile:** Before surgical evacuation in a long-standing missed abortion, always check the **Platelet count and Fibrinogen levels**. * **Management:** If the patient is stable and coagulation is normal, medical induction (e.g., Misoprostol) or surgical evacuation is performed. If DIC is present, stabilize with blood products (FFP, Cryoprecipitate) before intervention.
Question 518: Recurrent abortion in the first trimester is most often due to what cause?
- A. Chromosomal abnormalities (Correct Answer)
- B. Uterine anomaly
- C. Hormonal disturbance
- D. Infection
Explanation: **Explanation:** **1. Why Chromosomal Abnormalities are the Correct Answer:** Chromosomal abnormalities are the single most common cause of spontaneous pregnancy loss, especially in the **first trimester** (up to 12 weeks). In cases of recurrent pregnancy loss (RPL), parental chromosomal rearrangements (like balanced translocations) or sporadic embryonic aneuploidy account for the majority of early losses. Among these, **Autosomal Trisomy** is the most frequent specific chromosomal anomaly found in abortuses, followed by Monosomy X (Turner syndrome) and Polyploidy. **2. Analysis of Incorrect Options:** * **B. Uterine Anomaly:** Structural issues (e.g., septate uterus, cervical incompetence, or fibroids) are significant causes of recurrent abortion but are more characteristically associated with **second-trimester** losses rather than early first-trimester ones. * **C. Hormonal Disturbance:** Conditions like Luteal Phase Defect (LPD), uncontrolled Diabetes Mellitus, and Thyroid disorders can cause miscarriage. However, statistically, they occur less frequently than genetic factors in the first trimester. * **D. Infection:** While certain infections (TORCH, Mycoplasma) can cause sporadic pregnancy loss, they are **rarely** a cause of recurrent abortion, as the mother usually develops immunity after the initial exposure. **3. Clinical Pearls for NEET-PG:** * **Most common Trisomy in abortus:** Trisomy 16. * **Most common single chromosomal anomaly:** Monosomy X (45,X). * **Investigation of choice for RPL:** Karyotyping of both parents to rule out balanced translocations. * **Timing:** If the question specifies "Second Trimester," the most common cause shifts toward **Anatomical/Uterine factors** (specifically Cervical Incompetence).
Question 519: Which one of the following causes the greatest risk of ectopic pregnancy?
- A. Pelvic inflammatory disease
- B. IUD use
- C. Previous ectopic pregnancy (Correct Answer)
- D. Previous MTP
Explanation: **Explanation:** The risk of ectopic pregnancy is primarily determined by the degree of damage to the fallopian tube. **1. Why "Previous Ectopic Pregnancy" is correct:** A history of a previous ectopic pregnancy is the **strongest risk factor**, increasing the risk by approximately **10 to 15 times** compared to the general population. If a patient has had two or more prior ectopic pregnancies, the risk escalates to over 25%. This is due to underlying tubal pathology, scarring from previous surgery (salpingostomy), or persistent functional impairment of the cilia. **2. Analysis of Incorrect Options:** * **Pelvic Inflammatory Disease (PID):** While PID is the **most common** cause of ectopic pregnancy due to post-inflammatory tubal scarring and adhesions, it does not carry as high a relative risk as a prior ectopic event. * **IUD Use:** IUDs are highly effective contraceptives. They do not *cause* ectopic pregnancy; however, if a woman becomes pregnant with an IUD in situ, the **proportion** of those pregnancies being ectopic is higher. In absolute terms, IUD users have a lower risk of ectopic pregnancy than women using no contraception. * **Previous MTP:** Uncomplicated Medical Termination of Pregnancy (MTP) does not significantly increase the risk. Only if the procedure was complicated by post-abortal sepsis leading to tubal damage would the risk increase. **Clinical Pearls for NEET-PG:** * **Strongest Risk Factor:** Previous ectopic pregnancy. * **Most Common Cause:** Pelvic Inflammatory Disease (Chlamydia is the most common organism). * **Other High-Risk Factors:** Tubal reconstructive surgery, DES exposure in utero, and smoking (impairs ciliary motility). * **Classic Triad:** Amenorrhea, abdominal pain, and vaginal bleeding (seen in only 50% of cases).
Question 520: A woman presents with amenorrhea of 2 months duration, lower abdominal pain, facial pallor, fainting, and shock. What is the most likely diagnosis?
- A. Ruptured ovarian cyst
- B. Ruptured ectopic pregnancy (Correct Answer)
- C. Threatened abortion
- D. Septic abortion
Explanation: **Explanation:** The clinical presentation described is a classic medical emergency in early pregnancy. The correct diagnosis is **Ruptured Ectopic Pregnancy** based on the "Classic Triad" and signs of hemodynamic instability. **1. Why Ruptured Ectopic Pregnancy is Correct:** The patient presents with the hallmark features: **amenorrhea** (indicating pregnancy), **acute abdominal pain**, and **hypovolemic shock** (pallor, fainting, hypotension). In a ruptured ectopic pregnancy, the fallopian tube (most common site) bursts, leading to massive intraperitoneal hemorrhage (hemoperitoneum). This rapid blood loss causes the shock and fainting (syncope) described. **2. Why Other Options are Incorrect:** * **Ruptured Ovarian Cyst:** While it causes acute pain and potential hemoperitoneum, it is usually not associated with amenorrhea or a positive pregnancy status. * **Threatened Abortion:** This presents with vaginal bleeding and mild cramping, but the cervix is closed, and there is no hemodynamic collapse or signs of internal hemorrhage. * **Septic Abortion:** This involves infection of the products of conception. While it can cause shock (septic shock), it is characterized by high-grade fever, foul-smelling vaginal discharge, and exquisite uterine tenderness, rather than sudden fainting and pallor from blood loss. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of Ectopic Pregnancy:** Ampulla of the Fallopian tube. * **Most common site of Rupture:** Isthmus (occurs earlier, around 6–8 weeks). * **Gold Standard Investigation:** Transvaginal Ultrasound (TVUS) + Serum $\beta$-hCG (Correlation of "Discriminatory Zone"). * **Management of Rupture:** Immediate resuscitation followed by **emergency laparotomy** (Salpingectomy). * **Kehr’s Sign:** Referred pain to the shoulder due to diaphragmatic irritation by blood—a classic sign of ruptured ectopic pregnancy.
Practice by Chapter
Fetal Assessment Techniques
Practice Questions
Hypertensive Disorders in Pregnancy
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Intrauterine Growth Restriction
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Multiple Gestation
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Rh Isoimmunization and Other Blood Group Incompatibilities
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Intrauterine Fetal Therapy
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Prenatal Diagnosis and Genetic Counseling
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Placental Abnormalities
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Preterm Labor and Delivery
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Management of Medical Disorders in Pregnancy
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