Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 491: Which of the following tests is not used for the detection of specific aneuploidy?

A. FISH
B. Karyotyping
C. QF-PCR
D. Microarray (Correct Answer)

Explanation: **Explanation:** The core of this question lies in distinguishing between **numerical** chromosomal abnormalities (aneuploidy) and **structural** sub-microscopic abnormalities (copy number variants). **Why Microarray is the correct answer:** Chromosomal Microarray (CMA) is designed to detect **microdeletions and microduplications** (Copy Number Variations - CNVs) that are too small to be seen under a microscope. While it can detect unbalanced rearrangements, it is **not** the primary tool for specific aneuploidy detection because it cannot detect balanced translocations or triploidy effectively. In clinical practice, if a specific aneuploidy (like Trisomy 21) is suspected, rapid molecular tests or karyotyping are preferred. **Why the other options are incorrect:** * **FISH (Fluorescent In Situ Hybridization):** Uses fluorescent probes to bind to specific chromosomes (13, 18, 21, X, Y). It is a rapid gold-standard test for detecting specific aneuploidies in interphase nuclei. * **QF-PCR (Quantitative Fluorescent PCR):** Amplifies polymorphic microsatellite markers. It is the fastest method (24–48 hours) specifically used to diagnose common autosomal and sex chromosome aneuploidies. * **Karyotyping:** The traditional "gold standard" that provides a visual representation of all chromosomes. It identifies both numerical (aneuploidy) and large structural abnormalities (>5-10 Mb). **Clinical Pearls for NEET-PG:** * **Rapid Aneuploidy Testing:** FISH and QF-PCR are the preferred methods for quick results (e.g., following an abnormal prenatal screen). * **Microarray Indication:** It is the **first-line investigation** for a fetus with one or more structural ultrasound abnormalities but a normal karyotype. * **Karyotyping Limitation:** It requires cell culture (takes 2–3 weeks), whereas molecular methods (QF-PCR/FISH) do not. * **Triploidy:** QF-PCR is superior to Microarray in detecting triploidy.

Question 492: Which of the following congenital anomalies is seen with maternal use of cocaine?

A. Sacral agenesis
B. Hydrops
C. Cleft palate (Correct Answer)
D. Hypertrichosis

Explanation: **Explanation:** The correct answer is **C. Cleft palate.** **Mechanism of Action:** Cocaine is a potent sympathomimetic agent that acts as a powerful **vasoconstrictor**. It inhibits the reuptake of norepinephrine and dopamine at the presynaptic nerve terminals. In pregnancy, cocaine crosses the placenta and causes acute maternal and fetal hypertension and tachycardia. The primary mechanism for congenital anomalies is **vascular disruption**. Severe vasoconstriction leads to localized ischemia in developing fetal tissues, resulting in structural defects such as **cleft lip/palate**, segmental intestinal atresia, and limb reduction defects. **Analysis of Incorrect Options:** * **A. Sacral agenesis:** This is the most specific (pathognomonic) anomaly associated with **Maternal Diabetes Mellitus**, not cocaine use. * **B. Hydrops:** While cocaine can cause placental abruption or fetal growth restriction (FGR), it is not a classic cause of non-immune hydrops fetalis. Hydrops is more commonly associated with Rh isoimmunization, Parvovirus B19, or chromosomal anomalies. * **D. Hypertrichosis:** This (specifically synophrys/thick eyebrows) is a feature of **Fetal Alcohol Syndrome (FAS)** or certain genetic syndromes (e.g., Cornelia de Lange), but not cocaine exposure. **High-Yield Clinical Pearls for NEET-PG:** * **Most common complication:** Cocaine is most strongly associated with **Placental Abruption** (due to acute hypertension) and **IUGR/Fetal Growth Restriction**. * **Vascular Disruption Sequence:** Cocaine is linked to **Gastroschisis** and **Urinary tract anomalies** (e.g., prune belly syndrome) via the same ischemic mechanism. * **Neurobehavioral effects:** Neonates may present with irritability, tremors, and abnormal sleep patterns (often termed "Cocaine babies").

Question 493: A 25-year-old pregnant woman diagnosed with Rheumatic Heart Disease and Mitral Stenosis at 16 years of age presents at 6 weeks of gestation with a mitral valve area of 1.4 sq cm. She is currently in NYHA class 2 and on antiarrhythmic drugs. What is the risk of maternal mortality?

A. <1% (Correct Answer)
B. 50%
C. 15%
D. 5%

Explanation: **Explanation:** The risk of maternal mortality in cardiac disease is categorized based on the **Modified WHO (mWHO) Classification of Maternal Cardiovascular Risk**. 1. **Why A is correct:** This patient falls into **mWHO Class II**. * **Mitral Stenosis (MS)** is classified as mWHO II if it is mild (Valve area >1.5 cm²) or **moderate** (Valve area 1.0–1.5 cm²) and the patient is asymptomatic or mildly symptomatic (NYHA Class I or II). * For mWHO Class II, the risk of maternal mortality is extremely low, typically **<1%**. Although she is on antiarrhythmics, her valve area (1.4 cm²) and functional status (NYHA II) do not place her in a high-risk category. 2. **Why incorrect options are wrong:** * **Options B, C, and D (5% to 50%):** These high mortality rates are associated with **mWHO Class IV** conditions. These include Severe Mitral Stenosis (Valve area <1.0 cm²), Pulmonary Arterial Hypertension (Eisenmenger syndrome), and severe systemic ventricular dysfunction (EF <30%). In such cases, mortality can range from 10% to 50%, and pregnancy is generally contraindicated. **High-Yield Clinical Pearls for NEET-PG:** * **Most common heart disease in pregnancy (India):** Rheumatic Heart Disease (RHD). * **Most common lesion in RHD:** Mitral Stenosis. * **Critical MS:** Valve area **<1.0 cm²**. This is mWHO Class IV and carries a high risk of pulmonary edema and mortality. * **Most dangerous period:** The immediate postpartum period (first 24–48 hours) due to "autotransfusion" from the involuting uterus and relief of IVC compression, leading to sudden fluid overload. * **Management:** Beta-blockers are the mainstay for rate control in MS to allow adequate diastolic filling.

Question 494: When shoulder pain develops in a case of tubal pregnancy, what does it indicate?

A. Tubal abortion
B. Development of a tubal mole
C. Development of a broad ligament hematoma
D. Severe internal bleeding (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. Severe internal bleeding.** In the context of a ruptured ectopic pregnancy, shoulder tip pain is a classic clinical sign known as **Danforth’s Sign**. This occurs due to massive intraperitoneal hemorrhage (hemoperitoneum). The blood accumulates in the subdiaphragmatic space, causing irritation of the **phrenic nerve** (C3, C4, C5). Because the phrenic nerve shares the same spinal cord segments as the supraclavicular nerves, the pain is referred to the shoulder (dermatomes C3-C4). This indicates a surgical emergency and significant blood loss. **Analysis of Incorrect Options:** * **A. Tubal abortion:** While this involves the expulsion of the products of conception through the fimbrial end and can cause bleeding, it is often gradual and may form a pelvic hematocele rather than the massive, rapid bleeding required to reach the diaphragm. * **B. Tubal mole:** This occurs when the ovum dies but remains in the tube, surrounded by layers of blood clot. It is usually a contained process and does not typically cause massive intraperitoneal hemorrhage. * **C. Broad ligament hematoma:** This occurs in an extraperitoneal rupture (between the leaves of the broad ligament). Since the blood is contained within the ligament and does not enter the general peritoneal cavity to touch the diaphragm, it will not cause shoulder pain. **High-Yield Clinical Pearls for NEET-PG:** * **Kehr’s Sign:** Similar referred shoulder pain, but classically associated with a **ruptured spleen**. * **Cullen’s Sign:** Periumbilical ecchymosis (bluish discoloration) indicating intraperitoneal hemorrhage; seen in ruptured ectopic pregnancy or acute pancreatitis. * **Golden Rule:** Any woman of reproductive age presenting with amenorrhea, abdominal pain, and fainting/syncope should be evaluated for ruptured ectopic pregnancy until proven otherwise.

Question 495: Maternal Alpha-fetoprotein is increased in which of the following conditions?

A. Neural tube defects (Correct Answer)
B. Diabetes mellitus
C. Fetal cardiac defects
D. Rubella infection

Explanation: **Explanation:** **Alpha-fetoprotein (AFP)** is a glycoprotein synthesized by the fetal yolk sac and later by the fetal liver. It is the fetal equivalent of albumin. In a normal pregnancy, small amounts of AFP leak into the maternal circulation through the placenta. **Why Neural Tube Defects (NTDs) cause increased AFP:** In conditions like **Anencephaly** and **Open Spina Bifida**, there is a defect in the fetal skin or neural coverings. This allows AFP to leak directly from the fetal cerebrospinal fluid or exposed capillaries into the amniotic fluid, and subsequently into the maternal serum. Therefore, Maternal Serum AFP (MSAFP) is a primary screening tool for open NTDs. **Analysis of Incorrect Options:** * **Diabetes Mellitus:** Maternal diabetes is actually associated with **decreased** levels of MSAFP. The exact mechanism is unclear but may relate to delayed fetal growth or placental factors. * **Fetal Cardiac Defects:** These do not typically cause a breach in fetal integument; hence, AFP levels remain normal. * **Rubella Infection:** While intrauterine infections can cause various anomalies, they are not classically associated with elevated AFP. **High-Yield Clinical Pearls for NEET-PG:** * **Causes of Increased MSAFP:** Open NTDs, Multiple pregnancy (most common cause of "unexplained" elevation), Omphalocele, Gastroschisis, Renal anomalies (Finnish-type nephrosis), and Fetal demise. * **Causes of Decreased MSAFP:** Down Syndrome (Trisomy 21), Trisomy 18, Maternal Obesity, and Gestational Trophoblastic Disease. * **Screening Window:** MSAFP is ideally measured between **15–20 weeks** (Second Trimester). * **Next Step:** If MSAFP is elevated, the first step is a **Targeted Ultrasound** to confirm gestational age and rule out multiple pregnancies or visible defects.

Question 496: Which of the following is the most appropriate imaging modality to detect an abnormally located placenta?

A. Transvaginal Ultrasound (TVS) (Correct Answer)
B. Magnetic Resonance Imaging (MRI)
C. Doppler Ultrasound
D. Transabdominal Ultrasound (TAS)

Explanation: **Explanation:** The gold standard for the diagnosis and localization of an abnormally located placenta (Placenta Previa) is **Transvaginal Ultrasound (TVS)**. **1. Why Transvaginal Ultrasound (TVS) is the Correct Answer:** TVS is significantly more accurate than Transabdominal Ultrasound (TAS) for several reasons: * **Superior Resolution:** The high-frequency probe is closer to the cervix, providing better visualization of the internal os and the placental edge. * **Safety:** Contrary to older myths, TVS is safe in placenta previa as the probe does not enter the cervical canal; it remains in the vaginal fornix. * **Precision:** It eliminates the "false positive" diagnoses often caused by an overdistended bladder or focal myometrial contractions during TAS. **2. Why Other Options are Incorrect:** * **Transabdominal Ultrasound (TAS):** While often the initial screening tool, it has a higher false-positive rate (up to 25%). It is limited by maternal obesity, posterior placental location (shadowing from the fetal head), and bladder volume. * **Magnetic Resonance Imaging (MRI):** While excellent for diagnosing **Placenta Accreta Spectrum (PAS)**, it is not the primary modality for simple placental localization due to high cost and limited availability. * **Doppler Ultrasound:** This is primarily used to assess fetal well-being (umbilical artery) or to look for hypervascularity in cases of suspected morbidly adherent placenta, not for basic localization. **High-Yield Clinical Pearls for NEET-PG:** * **Distance Rule:** If the placental edge is **<2 cm** from the internal os but not covering it, it is termed a "low-lying placenta." * **Placental Migration:** Most "low-lying" placentas diagnosed in the second trimester resolve by the third trimester due to the development of the lower uterine segment (trophotropism). * **Warning:** Digital vaginal examination is strictly **contraindicated** in suspected placenta previa until the diagnosis is ruled out by TVS.

Question 497: What is the appropriate management of seizures complicating hypertension during pregnancy?

A. Magnesium sulfate intravenously or intramuscularly as per Pritchard's regimen (Correct Answer)
B. Pethidine, promethazine, chlorpromazine as 'Lytic cocktail'
C. Intravenous Hydralazine
D. Lethal (Benzodiazepine) regimen

Explanation: **Explanation:** The occurrence of seizures in a patient with pre-eclampsia defines **Eclampsia**, an obstetric emergency. **1. Why Magnesium Sulfate (MgSO₄) is the Correct Answer:** Magnesium sulfate is the **drug of choice** for both the prevention and treatment of eclamptic seizures. Large-scale clinical trials (Collaborative Eclampsia Trial) proved it is superior to diazepam and phenytoin in preventing recurrent seizures and reducing maternal mortality. It acts by increasing the seizure threshold and causing cerebral vasodilation. The **Pritchard’s Regimen** (Intramuscular) and **Zuspan’s Regimen** (Intravenous) are the standard protocols used globally. **2. Why the Other Options are Incorrect:** * **Option B (Lytic Cocktail):** Historically used (Menon’s regimen), this combination causes significant maternal sedation and neonatal respiratory depression. It is now obsolete. * **Option C (IV Hydralazine):** This is an antihypertensive used to manage hypertensive crises (Systolic BP ≥160 or Diastolic BP ≥110 mmHg). While it controls blood pressure, it does **not** treat or prevent seizures. * **Option D (Benzodiazepines):** While benzodiazepines (like Diazepam) can stop an active seizure, they are associated with a higher rate of seizure recurrence and maternal/fetal depression compared to MgSO₄. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Range of MgSO₄:** 4–7 mEq/L. * **First Sign of Toxicity:** Loss of Patellar Reflex (Knee jerk) at 7–10 mEq/L. * **Respiratory Depression:** Occurs at >12 mEq/L. * **Antidote:** 10 ml of 10% **Calcium Gluconate** IV (administered over 10 minutes). * **Monitoring:** Always check urine output (>30ml/hr), respiratory rate (>12-14/min), and deep tendon reflexes before giving repeat doses.

Question 498: A 38-week pregnant woman delivered a baby without upper limbs. What is a possible cause?

A. Amniotic band (Correct Answer)
B. True knot of umbilical cord
C. Genetic abnormality
D. None of the above

Explanation: **Explanation:** The correct answer is **Amniotic Band Syndrome (ABS)**. This condition occurs due to the premature rupture of the amnion, leading to the formation of fibrous, sticky bands. These bands can entangle, constrict, or amputate developing fetal parts, most commonly the distal limbs and digits. When these bands encircle a limb early in gestation, they can lead to complete **congenital amputation** or transverse limb defects, explaining the absence of upper limbs in this neonate. **Analysis of Incorrect Options:** * **B. True knot of umbilical cord:** While a true knot can lead to fetal distress or intrauterine fetal death (IUFD) due to compromised blood flow, it does not cause structural limb defects or amputations. * **C. Genetic abnormality:** While certain genetic syndromes (like Roberts syndrome) can cause limb reduction defects (phocomelia), they are usually symmetrical and associated with other dysmorphic features. Amniotic band syndrome is typically **asymmetrical and sporadic**, making it a more classic cause for isolated limb absence in a non-syndromic presentation. **High-Yield Clinical Pearls for NEET-PG:** * **Pathogenesis:** The most widely accepted theory is the **Torpin Theory** (Exogenous theory), which suggests that amnion rupture leads to "entrapment" by fibrous bands. * **Clinical Presentation:** Look for "constriction rings" on limbs, pseudo-syndactyly (fused fingers), or asymmetric amputations. * **Associated Defects:** ABS is also linked to craniofacial clefts and body wall defects (e.g., gastroschisis) if the bands involve the head or abdomen. * **Risk Factors:** It is generally a **sporadic event** with a very low recurrence risk in subsequent pregnancies.

Question 499: Increased gestational period is associated with which congenital anomaly?

A. Spina bifida
B. Anencephaly (Correct Answer)
C. Meningomyelocele
D. Omphalocele

Explanation: **Explanation:** The correct answer is **Anencephaly**. **Why Anencephaly is the correct answer:** Anencephaly is a neural tube defect characterized by the absence of a major portion of the brain, skull, and scalp. The association with an increased gestational period (post-term pregnancy) is due to the **absence of the fetal pituitary-adrenal axis**. In a normal pregnancy, the fetal hypothalamus-pituitary-adrenal (HPA) axis triggers the production of cortisol, which serves as a crucial precursor for the hormonal cascade (including estrogen surge and progesterone withdrawal) that initiates labor. In anencephalic fetuses, the lack of a functional hypothalamus and pituitary gland leads to adrenal hypoplasia and a failure to initiate the physiological "signal" for labor, resulting in prolonged pregnancy. **Why other options are incorrect:** * **Spina Bifida and Meningomyelocele:** While these are also neural tube defects, they involve the spinal column rather than the cranial vault. The fetal HPA axis remains intact in these conditions; therefore, they do not typically interfere with the hormonal initiation of labor or cause post-term pregnancy. * **Omphalocele:** This is a ventral abdominal wall defect. It has no physiological link to the endocrine triggers of labor and is more commonly associated with chromosomal anomalies (like Trisomy 18) or preterm birth rather than post-term. **High-Yield Clinical Pearls for NEET-PG:** * **Polyhydramnios:** Anencephaly is frequently associated with polyhydramnios because the fetus lacks the swallowing reflex. * **Alpha-Fetoprotein (AFP):** Maternal serum AFP is significantly **elevated** in open neural tube defects like anencephaly. * **"Frog-like" Appearance:** On ultrasound or physical examination, the absence of the cranial vault and bulging eyes give the fetus a characteristic "frog-like" facies. * **Fetal Adrenal Glands:** In anencephaly, the adrenal glands are extremely small (hypoplastic) due to the lack of ACTH stimulation.

Question 500: What hormone is responsible for the decidual and Arias-Stella reaction in ectopic pregnancy?

A. HCG
B. Progesterone (Correct Answer)
C. Estrogen
D. HPL

Explanation: **Explanation:** The correct answer is **Progesterone**. In an ectopic pregnancy, the body undergoes hormonal changes similar to a normal intrauterine pregnancy. The corpus luteum produces high levels of **progesterone**, which acts on the endometrium to prepare it for implantation. This leads to the **decidual reaction**—the transformation of endometrial stromal cells into large, lipid-rich polygonal cells. The **Arias-Stella reaction** is a specific histological change characterized by nuclear hypertrophy, hyperchromasia, and cytoplasmic vacuolation within the endometrial glands. It represents an exaggerated response of the endometrial glands to high levels of circulating progesterone. Importantly, these changes occur regardless of the location of the pregnancy (intrauterine or ectopic) because they are hormonally mediated. **Why other options are incorrect:** * **HCG (Human Chorionic Gonadotropin):** While HCG maintains the corpus luteum, it does not directly cause the decidual or Arias-Stella changes in the endometrial tissue. * **Estrogen:** Estrogen causes endometrial proliferation, but the secretory and decidual changes required for these reactions are specifically mediated by progesterone. * **HPL (Human Placental Lactogen):** HPL is involved in maternal metabolism and insulin resistance; it has no role in the morphological transformation of the endometrium. **High-Yield Clinical Pearls for NEET-PG:** * **Arias-Stella Reaction:** It is **not pathognomonic** for ectopic pregnancy; it can be seen in intrauterine pregnancies and gestational trophoblastic disease. * **Decidua without Villi:** On uterine curettage, the presence of decidua but the **absence of chorionic villi** is highly suggestive of an ectopic pregnancy (though not definitive). * The Arias-Stella reaction can sometimes be misdiagnosed as clear cell carcinoma due to its cellular atypia.

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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