Maternal-Fetal Medicine Practice Questions

Q: Betamethasone in pregnancy is given to prevent which of the following complications?

Respiratory distress syndrome. **Explanation:** **Betamethasone** is a corticosteroid administered to pregnant women at risk of preterm delivery (between 24 and 34 weeks of gestation) to accelerate fetal lung maturity. **Why Respiratory Distress Syndrome (RDS) is the correct answer:** The primary mechanism of Betamethasone is the induction of **Type II pneumocytes** in the fetal lungs. This stimulation increases the production and release of **surfactant**, which reduces alveolar surface tension. Adequate surfactant prevents alveolar collapse upon expiration, thereby significantly reducing the incidence and severity of RDS, intraventricular hemorrhage (IVH), and necrotizing enterocolitis (NEC). **Analysis of Incorrect Options:** * **A. Prematurity:** Betamethasone does not prevent preterm labor or birth; it only improves the neonatal outcomes associated with being born early. Tocolytics are used to delay prematurity. * **B. Neonatal convulsions:** These are typically caused by metabolic disturbances (hypoglycemia/hypocalcemia) or birth asphyxia, not steroid deficiency. * **C. Cerebral palsy:** While steroids reduce IVH (a risk factor for CP), they are not the primary preventive agent. **Magnesium sulfate** is the drug of choice for neuroprotection to reduce the risk of cerebral palsy in imminent preterm births. **High-Yield Clinical Pearls for NEET-PG:** * **Standard Dose:** 12 mg intramuscularly, 2 doses, 24 hours apart. * **Drug of Choice:** Betamethasone is preferred over Dexamethasone because it has a longer half-life and is associated with a lower risk of periventricular leukomalacia. * **Time to Benefit:** Maximum benefit occurs 24 hours after the first dose and lasts for up to 7 days. * **Indication:** All women between **24–34 weeks** at risk of delivery within 7 days. (Recent guidelines extend this to 36 weeks 6 days in specific "late preterm" scenarios).

Q: A 30-year-old primigravida complains of vaginal bleeding, pain in the abdomen, and vomiting. The uterus is enlarged, soft, and non-tender. Based on the ultrasound findings, what is the most likely diagnosis?

Hydatidiform mole. ***Hydatidiform mole*** - Classic presentation of **vaginal bleeding**, **hyperemesis gravidarum** (severe vomiting), and **enlarged soft uterus** in a primigravida strongly suggests molar pregnancy. - Ultrasound shows characteristic **"snowstorm" appearance** with grape-like vesicular pattern and absence of fetal structures. *Missed abortion* - Features **retained dead fetus** with **closed cervix** and **absence of cardiac activity** on ultrasound, not the snowstorm pattern. - Typically presents with **minimal bleeding** and **cramping pain**, with uterus smaller than expected for gestational age. *Blighted ovum* - Shows **empty gestational sac** without embryonic structures on ultrasound, lacking the vesicular pattern of molar pregnancy. - Usually presents with **mild bleeding** and **cramping**, without the severe vomiting seen in this case. *Ectopic pregnancy* - Occurs when pregnancy implants **outside the uterine cavity**, most commonly in **fallopian tubes**. - Presents with **severe unilateral pain**, **amenorrhea**, and potential **hemodynamic instability**, not an enlarged soft uterus.

Q: Maximum cardiac output during pregnancy is typically observed at which gestational age?

34 weeks. **Explanation:** The correct answer is **34 weeks**. During pregnancy, the maternal cardiovascular system undergoes significant physiological adaptations to meet the metabolic demands of the fetus. Cardiac output (CO) begins to increase as early as 5 weeks gestation, primarily due to an increase in stroke volume and later, an increase in heart rate. **Why 34 weeks is correct:** Cardiac output increases progressively throughout the first and second trimesters, reaching its peak (approximately 30–50% above pre-pregnancy levels) between **32 and 34 weeks** of gestation. After this point, it typically plateaus until the onset of labor. **Analysis of Incorrect Options:** * **A (20 weeks):** While CO is significantly elevated by this stage, it has not yet reached its maximum plateau. * **B (30 weeks):** This is close to the peak, but the maximum physiological rise is traditionally cited at the 34-week mark. * **D (36 weeks):** By 36 weeks, the CO has usually plateaued or may even appear slightly decreased in the supine position due to **aortocaval compression** by the gravid uterus, which reduces venous return. **High-Yield Clinical Pearls for NEET-PG:** * **Maximum CO overall:** The absolute peak of cardiac output occurs **immediately postpartum** (up to 60–80% increase) due to the "autotransfusion" of blood from the involuting uterus and the relief of caval compression. * **Labor:** CO increases by an additional 15% in the first stage and 50% in the second stage of labor. * **Clinical Significance:** Patients with underlying heart disease (e.g., Mitral Stenosis) are at the highest risk of heart failure at **32–34 weeks** and during the **immediate postpartum period**.

Q: A woman presents with amenorrhea of 6 weeks duration and a lump in the right iliac fossa. What is the investigation of choice?

Ultrasound (USG) abdomen. **Explanation:** The clinical presentation of **amenorrhea** followed by a **palpable mass in the iliac fossa** is a classic "red flag" for an **Ectopic Pregnancy** until proven otherwise. Other differentials include a corpus luteum cyst or a tubo-ovarian mass. **1. Why Ultrasound (USG) is the Investigation of Choice:** USG (specifically Transvaginal Sonography/TVS) is the gold standard initial investigation for any woman of reproductive age presenting with early pregnancy complications. It is non-invasive, cost-effective, and highly sensitive in identifying an intrauterine vs. extrauterine gestational sac. In this case, USG can confirm the location of the pregnancy, assess the nature of the iliac mass, and check for free fluid (hemoperitoneum) in the Pouch of Douglas. **2. Why other options are incorrect:** * **Laparoscopy:** While it is the *gold standard for diagnosis* and allows for simultaneous treatment, it is an invasive surgical procedure. It is reserved for cases where USG is inconclusive or the patient is hemodynamically unstable. * **CT Scan:** CT is contraindicated in early pregnancy due to high ionizing radiation (teratogenic risk) and provides inferior soft-tissue detail of the pelvis compared to USG. * **Shielded X-ray:** X-rays have no role in diagnosing early pregnancy or adnexal masses and expose the fetus to unnecessary radiation. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad of Ectopic Pregnancy:** Amenorrhea, abdominal pain, and vaginal bleeding (present in only 50% of cases). * **Discriminatory Zone:** The level of serum β-hCG (usually 1500–2000 mIU/ml) at which an intrauterine gestational sac should be visible on TVS. * **Arias-Stella Reaction:** Hypersecretory endometrium seen on biopsy in ectopic pregnancy (due to hormonal stimulation without an intrauterine sac).

Q: What ultrasound findings suggest cervical incompetence?

All of the above. **Cervical Incompetence** (also known as Cervical Insufficiency) is the inability of the uterine cervix to retain a pregnancy in the second trimester in the absence of clinical contractions. It is a structural weakness that leads to painless cervical dilatation and subsequent preterm birth or mid-trimester miscarriage. ### **Explanation of Ultrasound Findings** Transvaginal Ultrasound (TVS) is the gold standard for diagnosing cervical changes. The correct answer is **D** because all three findings are progressive markers of cervical failure: 1. **Shortened Cervical Length:** A cervical length of **<25 mm** before 24 weeks of gestation is the most significant predictor of preterm birth. 2. **Funneling of the Internal Os:** This occurs when the internal os opens but the external os remains closed. It is often described by the shapes **T, Y, V, and U** (mnemonic: **"Trust Your Vaginal Ultrasound"**), where 'U' represents the most advanced stage of funneling. 3. **Widening of the Internal Os:** As the cervix weakens, the internal os dilates, often allowing the fetal membranes to prolapse into the cervical canal (the "hourglass" membranes sign). ### **Why other options are incorrect** Options A, B, and C are individual components of the same pathological process. Selecting only one would be incomplete, as they often occur concurrently or sequentially during the "shortening and funneling" process. ### **NEET-PG High-Yield Pearls** * **Gold Standard Diagnosis:** History-based (recurrent mid-trimester losses) or TVS-based (cervical length <25 mm). * **McDonald’s and Shirodkar’s Operations:** These are the two common types of cervical cerclage. * **Best Time for Cerclage:** Usually performed between **12–14 weeks** of gestation. * **The "Stress Test":** Applying fundal pressure during ultrasound can elicit funneling that is not visible at rest, helping in early diagnosis.

Q: What is the best method for the diagnosis of lung maturity?

Phosphatidyl glycerol estimation in amniotic fluid. **Explanation:** The assessment of fetal lung maturity (FLM) depends on the presence of pulmonary surfactants in the amniotic fluid. **Why Phosphatidylglycerol (PG) is the best method:** Phosphatidylglycerol is a minor constituent of surfactant that appears late in gestation (usually after 35–36 weeks). Its presence is the **most reliable and specific indicator** of lung maturity. Unlike the L/S ratio, PG estimation is **not affected by contamination** with blood, meconium, or vaginal secretions, making it the "gold standard" for accuracy in complicated pregnancies. **Analysis of Incorrect Options:** * **Lecithin/Sphingomyelin (L/S) ratio:** Historically the most common test. A ratio >2:1 indicates maturity. However, it is highly sensitive to contamination (blood/meconium) and has a higher false-positive rate in diabetic pregnancies compared to PG. * **Bilirubin in amniotic fluid:** Measured via spectrophotometry ($\Delta OD_{450}$), this is used to assess the severity of **Rh-isoimmunization** and fetal hemolysis, not lung maturity. * **Amniotic fluid creatinine:** This reflects **fetal renal maturity** and muscle mass. While levels >2 mg/dL correlate with a gestational age of >37 weeks, it is not a direct or reliable measure of pulmonary surfactant. **High-Yield Clinical Pearls for NEET-PG:** * **Most sensitive/earliest test:** L/S ratio. * **Most specific test (Best):** Phosphatidylglycerol (PG). * **Rapid bedside test:** Shake test (Bubble stability test). * **Diabetes Mellitus:** PG is particularly useful here because the L/S ratio can be >2:1 while the lungs are still immature (delayed maturation). * **Lamellar Body Count (LBC):** A modern, rapid automated test; a count >30,000-50,000/µL indicates maturity.

Q: Which of the following genital infections carries the highest risk for preterm delivery?

Bacterial vaginitis. **Explanation:** **Bacterial Vaginosis (BV)** is the most significant genital infection associated with adverse pregnancy outcomes, particularly **preterm labor (PTL)** and **preterm premature rupture of membranes (PPROM)**. The underlying mechanism involves a shift in vaginal flora from protective *Lactobacilli* to anaerobic organisms (e.g., *Gardnerella vaginalis*, *Mobiluncus*). These bacteria produce inflammatory cytokines, prostaglandins, and phospholipase A2, which stimulate uterine contractions and weaken fetal membranes, leading to cervical ripening and preterm delivery. **Analysis of Options:** * **Bacterial Vaginosis (Correct):** It increases the risk of preterm birth by approximately 2-fold. It is also linked to late miscarriages and postpartum endometritis. * **Trichomonas vaginitis:** While associated with some adverse outcomes, the correlation with preterm delivery is significantly weaker than BV. Interestingly, treating asymptomatic Trichomoniasis in pregnancy has not been proven to reduce preterm birth rates. * **Monilial (Candidiasis) vaginitis:** This is very common in pregnancy due to high estrogen levels but is considered a commensal overgrowth. It does **not** increase the risk of preterm labor. * **Human Papilloma Virus (HPV):** This is a viral infection primarily associated with cervical dysplasia and genital warts. It does not have a recognized causal link with preterm delivery. **NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis for BV:** Nugent Scoring (Gram stain). * **Clinical Diagnosis:** Amsel’s Criteria (requires 3 out of 4: Thin white discharge, pH >4.5, +ve Whiff test, and **Clue cells**). * **Treatment in Pregnancy:** Oral Clindamycin or Metronidazole is recommended to symptomatic patients to alleviate symptoms, though it may not always prevent preterm birth once the inflammatory cascade has begun.

Question 1

Betamethasone in pregnancy is given to prevent which of the following complications?

Accepted Answer

Respiratory distress syndrome

Answer

Prematurity

Answer

Neonatal convulsions

Answer

Cerebral palsy

Question 2

A 30-year-old primigravida complains of vaginal bleeding, pain in the abdomen, and vomiting. The uterus is enlarged, soft, and non-tender. Based on the ultrasound findings, what is the most likely diagnosis?

Accepted Answer

Hydatidiform mole

Answer

Missed abortion

Answer

Blighted ovum

Answer

Ectopic pregnancy

Question 3

An 8th-month primigravida presented with severe pruritus and mild icterus. Her serum bilirubin was 3 mg/dL, with elevated AST, ALT, and alkaline phosphatase. Her renal function tests and coagulation profile were within normal limits. What is the most likely diagnosis?

Accepted Answer

Obstetric cholestasis

Answer

HELLP syndrome

Answer

Hepatorenal syndrome

Answer

Viral hepatitis

Question 4

Maximum cardiac output during pregnancy is typically observed at which gestational age?

Accepted Answer

34 weeks

Answer

20 weeks

Answer

30 weeks

Answer

36 weeks

Question 5

All of the following statements about prenatal steroids are true except?

Accepted Answer

These can be given even in the presence of chorioamnionitis.

Answer

They cause a 50% reduction in respiratory distress syndrome and intraventricular hemorrhage.

Answer

These are advocated for mothers at risk of preterm delivery between 24-34 weeks of gestation.

Answer

These can be safely administered to mothers with hypertension or diabetes.

Question 6

A woman presents with amenorrhea of 6 weeks duration and a lump in the right iliac fossa. What is the investigation of choice?

Accepted Answer

Ultrasound (USG) abdomen

Answer

Laparoscopy

Answer

CT scan

Answer

Shielded X-ray

Question 7

Paradoxical incontinence of urine in a primigravida is seen with which of the following conditions?

Accepted Answer

Retroflexion of the uterus

Answer

Anteflexion of the uterus

Answer

Sacculation

Answer

Uterine prolapse

Question 8

What ultrasound findings suggest cervical incompetence?

Accepted Answer

All of the above

Answer

Shortened cervical length

Answer

Funneling of the internal os

Answer

Widening of the internal os

Question 9

What is the best method for the diagnosis of lung maturity?

Accepted Answer

Phosphatidyl glycerol estimation in amniotic fluid

Answer

Lecithin/Sphingomyelin (L/S) ratio in amniotic fluid

Answer

Bilirubin in amniotic fluid

Answer

Amniotic fluid creatinine

Question 10

Which of the following genital infections carries the highest risk for preterm delivery?

Accepted Answer

Bacterial vaginitis

Answer

Trichomonas vaginitis

Answer

Monilial vaginitis

Answer

Human papilloma virus

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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