Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 731: All are true about cancers during pregnancy, except:

A. Cancer develops during approximately 1 in every 1000 pregnancies.
B. Of all cancers that occur in women, less than 1% are seen in pregnant ladies.
C. The four cancers most commonly developing during pregnancy are cervical cancer, breast cancer, melanoma, and lymphoma (usually Hodgkin's lymphoma).
D. Lymphoma is the most common cancer during pregnancy. (Correct Answer)

Explanation: **Explanation** The incidence of cancer during pregnancy is relatively low, but it remains a significant clinical challenge. **1. Why Option D is the correct answer (The Exception):** While lymphoma (specifically Hodgkin’s lymphoma) is one of the most common malignancies in pregnancy, it is **not the most common**. Statistically, **Breast Cancer** is the most frequently diagnosed cancer during pregnancy, followed closely by cervical cancer. Therefore, the statement that lymphoma is the most common is incorrect. **2. Analysis of Incorrect Options:** * **Option A:** This is a statistically accurate statement. The incidence of malignancy complicating pregnancy is approximately **1 in 1,000 pregnancies**. * **Option B:** Because most cancers occur in older age groups, only a small fraction (**less than 1%**) of all female cancers are diagnosed during pregnancy. * **Option C:** This list correctly identifies the "Big Four" malignancies associated with pregnancy. **Breast cancer** (1 in 3,000) and **Cervical cancer** (1 in 2,500) are the most prevalent, followed by **Melanoma** and **Lymphoma**. **NEET-PG High-Yield Pearls:** * **Most common cancer in pregnancy:** Breast Cancer. * **Most common gynecological cancer in pregnancy:** Cervical Cancer. * **Diagnostic Caveat:** Pregnancy-associated breast cancer (PABC) is often diagnosed at a later stage due to physiological changes (engorgement/lactation) masking lumps. * **Management Rule:** Termination of pregnancy does not generally improve the prognosis of the maternal cancer. * **Chemotherapy:** Generally contraindicated in the 1st trimester (organogenesis) but can often be administered in the 2nd and 3rd trimesters. * **Radiotherapy:** Usually contraindicated throughout pregnancy due to fetal risks.

Question 732: In diabetes, which of the following can occur in the fetus?

A. Pre-eclampsia
B. Polyhydramnios
C. Fetal anomalies (Correct Answer)
D. Abruptio placentae

Explanation: **Explanation:** The correct answer is **C. Fetal anomalies**. In pregnancies complicated by diabetes (especially pre-gestational diabetes), maternal hyperglycemia during the period of organogenesis (first 8 weeks) is highly teratogenic. High glucose levels lead to the production of reactive oxygen species and oxidative stress, which interfere with normal gene expression and cellular development. The most common anomalies are **cardiac** (e.g., Transposition of Great Arteries, VSD), but the most specific anomaly is **Caudal Regression Syndrome** (Sacral Agenesis). **Analysis of Options:** * **A. Pre-eclampsia:** While diabetes is a significant risk factor for developing pre-eclampsia, this is a **maternal complication**, not a fetal one. * **B. Polyhydramnios:** This is a common **obstetric complication** associated with fetal hyperglycemia-induced osmotic diuresis (fetal polyuria). However, it is a condition of the amniotic fluid volume, not a structural anomaly of the fetus itself. * **D. Abruptio placentae:** This is more commonly associated with hypertensive disorders and trauma. Diabetes is typically associated with placental hypertrophy, not premature separation. **NEET-PG High-Yield Pearls:** * **Most Common Anomaly:** Ventricular Septal Defect (VSD). * **Most Specific Anomaly:** Caudal Regression Syndrome. * **HbA1c Correlation:** The risk of malformations increases significantly if HbA1c is >8.5% during the first trimester. * **Neural Tube Defects:** These are 10 times more common in diabetic pregnancies compared to the general population. * **Neonatal Complications:** Hypoglycemia, hypocalcemia, hyperbilirubinemia, and polycythemia.

Question 733: Which of the following is NOT a cause of hydramnios?

A. Anencephaly
B. Esophageal atresia
C. Posterior urethral valve (Correct Answer)
D. Twins

Explanation: **Explanation:** The volume of amniotic fluid is a dynamic balance between production (primarily fetal urine) and removal (primarily fetal swallowing). **Hydramnios (Polyhydramnios)** occurs when there is either excessive production of urine or an inability of the fetus to swallow and absorb fluid. **Why Posterior Urethral Valve (PUV) is the correct answer:** PUV is a condition found in male fetuses where an obstructing membrane in the urethra prevents the bladder from emptying. This leads to **reduced fetal urine output** (oliguria/anuria). Since fetal urine is the primary source of amniotic fluid in the second and third trimesters, PUV results in **Oligohydramnios**, not hydramnios. **Analysis of Incorrect Options:** * **Anencephaly:** Causes hydramnios due to two mechanisms: the absence of the swallowing reflex and the transudation of fluid from the exposed meninges (cerebrospinal fluid) into the amniotic sac. * **Esophageal Atresia:** This creates a mechanical GI tract obstruction. The fetus is unable to swallow amniotic fluid, preventing its absorption by the intestines, leading to fluid accumulation. * **Twins:** Multiple gestations (especially Monochorionic) are associated with hydramnios, often due to Twin-to-Twin Transfusion Syndrome (TTTS), where the recipient twin develops polyuria. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** Amniotic Fluid Index (AFI) > 25 cm or Single Deepest Pocket (SDP) > 8 cm. * **Most common cause:** Idiopathic (approx. 50-60%), followed by Maternal Diabetes. * **Mnemonic for Oligohydramnios (DRIPPC):** **D**eath of fetus, **R**enal agenesis (Potter’s), **I**UGR, **P**rom (Premature Rupture of Membranes), **P**ost-term pregnancy, **C**hromosomal anomalies.

Question 734: A 33-year-old patient has an infection during pregnancy. Which of the following infections is a reactivation and therefore not a risk to the fetus?

A. Group B coxsackievirus
B. Rubella virus
C. Toxoplasmosis
D. Shingles (Correct Answer)

Explanation: **Explanation:** The core concept tested here is the difference between **primary infection** and **reactivation** during pregnancy. For most TORCH pathogens, the risk of vertical transmission and congenital anomalies is highest during a primary infection, as the mother lacks pre-existing antibodies to protect the fetus. **Why Shingles is the Correct Answer:** Shingles (Herpes Zoster) is the **reactivation** of the latent Varicella-Zoster Virus (VZV) in a person who has previously had chickenpox. Because the mother already possesses high titers of IgG antibodies from the initial infection, these antibodies cross the placenta and protect the fetus. Therefore, Shingles during pregnancy does **not** pose a risk of Congenital Varicella Syndrome. In contrast, a primary Varicella infection (chickenpox) in a pregnant woman is a medical emergency due to the risk of maternal pneumonia and fetal anomalies. **Analysis of Incorrect Options:** * **Group B Coxsackievirus:** This typically causes primary infections in pregnancy and can be associated with fetal myocarditis or neonatal systemic illness. * **Rubella Virus:** Primary infection is highly teratogenic (Congenital Rubella Syndrome), especially in the first trimester. Reactivation is clinically negligible and extremely rare. * **Toxoplasmosis:** Only a **primary** infection acquired during pregnancy poses a risk of congenital toxoplasmosis (triad of chorioretinitis, hydrocephalus, and intracranial calcifications). Chronic/latent infection is not a risk unless the mother is severely immunocompromised (e.g., HIV). **NEET-PG High-Yield Pearls:** * **Congenital Varicella Syndrome:** Risk is highest (approx. 2%) if primary infection occurs between **13–20 weeks** of gestation. * **Varicella Zoster Immunoglobulin (VZIG):** Should be given to susceptible pregnant women within 96 hours of exposure to chickenpox. * **Neonatal Varicella:** Occurs if the mother develops the rash 5 days before to 2 days after delivery; this is a high-mortality period for the newborn due to lack of maternal antibody transfer.

Question 735: During ultrasonography, fetal abdominal circumference is measured at the level of which structures?

A. Stomach and umbilical vein, perpendicular to the spine (Correct Answer)
B. Kidneys
C. Stomach, parallel to the spine
D. Liver and spleen

Explanation: **Explanation:** The **Abdominal Circumference (AC)** is the most sensitive ultrasound parameter for assessing fetal growth and detecting Intrauterine Growth Restriction (IUGR) or macrosomia, as it reflects the size of the liver and subcutaneous fat stores. **Why Option A is Correct:** To ensure accuracy and reproducibility, the AC must be measured at a specific transverse plane. The anatomical landmarks required are: 1. **The Stomach bubble:** Representing the left side. 2. **The Umbilical Vein (specifically the "J-shape" junction with the left portal vein):** This ensures the slice is not too low in the abdomen. 3. **The Spine:** The cross-section must be **perpendicular** to the spine to ensure a circular, rather than elliptical, measurement. **Why Other Options are Incorrect:** * **Option B (Kidneys):** The kidneys are located retroperitoneally and inferior to the ideal AC plane. Including them indicates the slice is too low, which would underestimate the circumference. * **Option C (Parallel to the spine):** A parallel (longitudinal) orientation would measure the length of the abdomen, not the circumference. * **Option D (Liver and Spleen):** While the liver occupies most of the AC plane, the spleen is not a standardized landmark for this measurement. **High-Yield Clinical Pearls for NEET-PG:** * **Formula:** $AC = 2\pi r$ (if circular) or $1.57 \times (D1 + D2)$ using the Hadlock method. * **IUGR:** AC is the first parameter to lag in **Asymmetrical IUGR** (Head-sparing effect). * **Technical Tip:** The umbilical vein should be seen within the liver, but it should **not** meet the anterior abdominal wall in the measurement plane. * **Accuracy:** AC has the largest reporting error among all fetal biometry parameters but is the best predictor of birth weight.

Question 736: Which of the following conditions is NOT associated with decreased variability of fetal heart rate?

A. Fetal movement (Correct Answer)
B. Chronic hypoxia
C. Sleep
D. Acidemia

Explanation: **Explanation:** Fetal heart rate (FHR) variability represents the beat-to-beat fluctuations in the baseline heart rate, reflecting a healthy, mature interaction between the sympathetic and parasympathetic nervous systems. **Why Fetal Movement is the Correct Answer:** Fetal movement is associated with **increased** variability and accelerations. When a fetus moves, the sympathetic nervous system is activated, causing a transient rise in heart rate (acceleration). This is a hallmark of fetal well-being and forms the basis of a "Reactive" Non-Stress Test (NST). Therefore, it is not a cause of decreased variability. **Analysis of Incorrect Options:** * **Sleep (Fetal Sleep Cycles):** This is the most common physiological cause of decreased variability. Fetal quiet sleep cycles usually last 20–40 minutes; during this time, the autonomic nervous system is less active, leading to a "flat" or minimally variable tracing. * **Chronic Hypoxia & Acidemia:** These are pathological causes. As the fetus becomes hypoxic or acidotic, the central nervous system (CNS) becomes depressed. This depression impairs the autonomic regulatory centers in the brainstem, leading to a loss of variability. Persistent absent variability combined with late decelerations is a sign of impending fetal compromise. **High-Yield Clinical Pearls for NEET-PG:** * **Normal Variability:** 6 to 25 beats per minute (Moderate). * **Drugs causing decreased variability:** Magnesium sulfate, opioids (morphine, pethidine), diazepam, and atropine. * **Saltatory Pattern:** Variability >25 bpm; often seen during acute hypoxia or umbilical cord compression. * **Sinusoidal Pattern:** A smooth, undulating wave-like pattern (variability is technically absent); classically associated with **severe fetal anemia** (Rh isoimmunization) or fetal hemorrhage.

Question 737: What is the drug of choice for hypertensive emergencies in pregnancy?

A. Methyldopa
B. Nitroprusside
C. Labetalol (Correct Answer)
D. Nicardipine

Explanation: **Explanation:** In the management of hypertensive emergencies in pregnancy (defined as BP ≥160/110 mmHg), the goal is to rapidly lower blood pressure to prevent maternal complications like intracranial hemorrhage without compromising uteroplacental blood flow. **1. Why Labetalol is the Correct Answer:** Labetalol is a non-selective beta-blocker with alpha-1 blocking activity (ratio of 1:7 for IV). It is considered the **first-line drug of choice** because of its rapid onset of action (5–10 minutes), excellent safety profile, and its ability to lower BP without causing significant reflex tachycardia. It maintains stable placental perfusion, making it ideal for acute management. **2. Analysis of Incorrect Options:** * **Methyldopa (A):** While it is the drug of choice for *chronic* hypertension in pregnancy, it is **not** used in emergencies due to its slow onset of action (4–6 hours) and sedative side effects. * **Nitroprusside (B):** It is generally avoided in pregnancy due to the risk of **fetal cyanide toxicity**. It is reserved only for refractory cases where all other agents fail. * **Nicardipine (D):** A calcium channel blocker that is effective, but it is typically considered a second-line or alternative agent to Labetalol and Hydralazine. **High-Yield Clinical Pearls for NEET-PG:** * **First-line agents for Acute Hypertensive Crisis:** IV Labetalol, IV Hydralazine, or Oral Nifedipine (immediate release). * **Contraindication for Labetalol:** Avoid in patients with asthma, heart failure, or bradycardia. * **Target BP:** Aim to lower the MAP by no more than 25% in the first hour, targeting a diastolic BP of 90–100 mmHg. * **ACE Inhibitors/ARBs:** Absolutely contraindicated in pregnancy (Teratogenic; cause fetal renal dysgenesis and oligohydramnios).

Question 738: Rubin's diagnostic criteria is used for which of the following conditions?

A. Ovarian pregnancy.
B. Hydatiform mole.
C. Cervical pregnancy. (Correct Answer)
D. Abdominal pregnancy.

Explanation: **Explanation:** **Rubin’s Criteria** are the established diagnostic benchmarks used to confirm a **Cervical Pregnancy**, a rare but life-threatening form of ectopic pregnancy where the blastocyst implants in the endocervical canal. **Why Cervical Pregnancy is Correct:** According to Rubin (1948), for a diagnosis of cervical pregnancy, the following four histological/anatomical criteria must be met: 1. Cervical glands must be opposite the placental attachment site. 2. The attachment of the placenta to the cervix must be intimate (below the internal os). 3. The whole or a portion of the placenta must be situated below the level of the internal os. 4. Fetal elements must be absent from the uterine cavity. **Analysis of Incorrect Options:** * **Ovarian Pregnancy:** Diagnosed using **Spiegelberg’s Criteria** (e.g., the tube on the affected side must be intact, the gestational sac must occupy the position of the ovary). * **Abdominal Pregnancy:** Diagnosed using **Studdiford’s Criteria** (e.g., normal tubes and ovaries with no evidence of recent pregnancy, no evidence of uteroperitoneal fistula). * **Hydatidiform Mole:** This is a gestational trophoblastic disease diagnosed via ultrasound ("snowstorm appearance") and serum beta-hCG levels, not by Rubin’s criteria. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Characterized by painless vaginal bleeding and a soft, "hourglass" shaped uterus (distended cervix larger than the fundus). * **Management:** Historically required hysterectomy due to profuse bleeding; currently managed conservatively with **Methotrexate** or uterine artery embolization. * **Key Distinction:** Do not confuse Rubin’s Criteria (Cervical Pregnancy) with the **Rubin Test** (Insufflation of fallopian tubes with $CO_2$ to check patency).

Question 739: During an antenatal check-up, a primigravida is found to be positive for Treponema pallidum infection. She is worried about her child. At which week of gestation does Treponema pallidum infection typically transfer to the fetus?

A. 4th week
B. 8th week
C. 16th week
D. 20th week (Correct Answer)

Explanation: **Explanation:** The transmission of *Treponema pallidum* (the causative agent of Syphilis) from the mother to the fetus occurs via the placenta. While the spirochetes can technically cross the placenta as early as the 9th week of gestation, the **pathological effects and established infection typically occur after the 16th to 20th week.** The correct answer is **20th week** because, prior to this period, the fetus is protected by the **Langhans layer** (cytotrophoblast) of the chorion. After the 16th week, this layer begins to atrophy, and by the 20th week, it disappears, making the placenta more permeable to the spirochetes. Furthermore, the fetal immune system only becomes capable of mounting an inflammatory response (which causes the characteristic tissue damage of congenital syphilis) after the 18th–20th week. **Analysis of Incorrect Options:** * **A & B (4th and 8th week):** During the first trimester, the Langhans layer is thick and well-developed, acting as a robust physical barrier against the transmission of large organisms like spirochetes. * **C (16th week):** While the Langhans layer begins to thin at this stage, the most significant risk and the standard teaching for established clinical infection is the 20th week. **Clinical Pearls for NEET-PG:** * **Treatment:** Penicillin G is the only effective treatment for preventing fetal infection and treating the fetus. If the mother is allergic, **desensitization** is mandatory. * **Jarisch-Herxheimer Reaction:** Pregnant women treated for syphilis must be monitored for this reaction, as it can trigger preterm labor or fetal distress. * **Screening:** All pregnant women should be screened at the first prenatal visit using non-treponemal tests (VDRL/RPR). * **Congenital Syphilis:** If untreated, it can lead to abortion, stillbirth, or neonatal features like snuffles, Hutchinson’s teeth, and Mulberry molars.

Question 740: Which test detects feto-maternal transfusion?

A. Kleihauer test (Correct Answer)
B. Spectrophotometry
C. Benzidine test
D. None of the above

Explanation: **Explanation:** The **Kleihauer-Betke (KB) test** is the gold standard for detecting and quantifying feto-maternal hemorrhage (FMH). **1. Why Kleihauer-Betke Test is Correct:** The test relies on the principle of **acid elution**. Fetal hemoglobin (HbF) is resistant to acid elution, whereas adult hemoglobin (HbA) is not. When a maternal blood smear is exposed to an acid bath, HbA is leached out of the maternal red cells, leaving them as pale "ghost cells." The fetal red cells retain their HbF and take up the eosin stain, appearing bright pink. This allows for the calculation of the volume of fetal blood in maternal circulation, which is crucial for determining the required dose of **Anti-D immunoglobulin** in Rh-negative mothers. **2. Why Other Options are Incorrect:** * **Spectrophotometry (Liley’s Chart):** This is used to analyze amniotic fluid for bilirubin levels (ΔOD450) to assess the severity of fetal hemolysis in Rh-isoimmunized pregnancies. It does not detect the transfusion itself. * **Benzidine Test:** This is a historical chemical test used to detect the presence of blood (hemoglobin) in urine or stools (occult blood). It is not specific to fetal blood. **3. High-Yield Clinical Pearls for NEET-PG:** * **Formula for Anti-D Dosage:** 1 vial (300 mcg) of Anti-D neutralizes **30 mL** of fetal whole blood (or 15 mL of packed RBCs). * **Calculation:** (Number of fetal cells / Total cells counted) × 5000 mL = Volume of FMH in mL. * **Screening vs. Quantitation:** The **Rosette test** is a qualitative screening test (sensitive but not quantitative); if positive, the KB test is performed to quantify the bleed. * **Modern Alternative:** Flow cytometry is increasingly replacing the KB test due to better precision and less human error.

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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