Maternal-Fetal Medicine Practice Questions

Q: A small-sized placenta is typically seen in which of the following conditions?

Pre-eclampsia. **Explanation:** The size and weight of the placenta are directly related to the surface area available for nutrient and oxygen exchange. A **small-sized placenta** (placental hypoplasia) occurs when there is impaired trophoblastic invasion or chronic uteroplacental insufficiency. **Why Pre-eclampsia is correct:** In pre-eclampsia, there is a failure of the secondary wave of trophoblastic invasion (at 16–20 weeks). This results in the spiral arteries remaining narrow and high-resistance, leading to reduced blood flow to the placental bed. The chronic ischemia causes placental infarcts, cytotrophoblastic proliferation, and villous hypoplasia, ultimately resulting in a small, underweight placenta. This is a classic cause of Fetal Growth Restriction (FGR). **Analysis of Incorrect Options:** * **Peripheral vascular disease:** While systemic, it does not specifically target the uterine spiral arteries like the localized pathology of pre-eclampsia. * **Maternal weight < 50 kg:** While maternal nutrition affects birth weight, a low BMI alone does not pathologically restrict placental growth unless associated with severe malnutrition or anemia. * **Multiple pregnancy:** This is a cause of a **large/heavy placenta** (or multiple placentas), as the increased fetal demand requires a larger surface area for exchange. **High-Yield Clinical Pearls for NEET-PG:** * **Large Placenta (Placentomegaly):** Seen in Diabetes Mellitus, Rh-isoimmunization, Syphilis, and Multiple pregnancy. * **Placental Weight:** The average weight at term is ~500g (Ratio of placental weight to fetal weight is 1:6). * **Microscopic hallmark of Pre-eclampsia:** Tenney-Parker changes (increased syncytial knots).

Q: Which of the following is NOT considered a high-risk pregnancy factor?

Vertex presentation. **Explanation:** In obstetrics, a **high-risk pregnancy** is one where the mother, the fetus, or the neonate is at an increased risk of morbidity or mortality before, during, or after delivery. **Why Vertex Presentation is the Correct Answer:** **Vertex presentation** is the most common and **normal (physiological)** presentation where the fetal head is well-flexed, allowing the smallest diameters of the skull to engage in the maternal pelvis. It is the ideal presentation for a spontaneous vaginal delivery and is not a risk factor; rather, it is the desired clinical finding. **Analysis of Incorrect Options (High-Risk Factors):** * **Elderly Primigravida:** Defined as a woman over **35 years** of age pregnant for the first time. It is high-risk due to increased associations with chromosomal abnormalities (Down syndrome), gestational diabetes, pre-eclampsia, and higher rates of operative interventions. * **Short Stature Primigravida:** Usually defined as a height **<140–145 cm**. This is a significant risk factor for **Cephalopelvic Disproportion (CPD)** and obstructed labor, often necessitating a Cesarean section. * **Diabetes:** Both pre-gestational and Gestational Diabetes Mellitus (GDM) are high-risk. They increase the risk of fetal macrosomia, shoulder dystocia, congenital malformations, and neonatal hypoglycemia. **NEET-PG High-Yield Pearls:** * **Malpresentations** (Breech, Transverse, Face, or Brow) are considered high-risk, unlike Vertex. * **Grand Multipara** (Para 4 or more) is also a high-risk factor due to risks of malpresentation, placenta previa, and postpartum hemorrhage (PPH). * **Previous Cesarean Section** is a major high-risk factor due to the risk of uterine rupture and morbidly adherent placenta (Placenta Accreta Spectrum).

Q: A female presents with 8 weeks of amenorrhea and left lower abdominal pain. Ultrasonography reveals a thick endometrium with a mass in the lateral adnexa. What is the most probable diagnosis?

Ectopic pregnancy. ### Explanation The clinical presentation of **amenorrhea, abdominal pain, and an adnexal mass** is the classic triad for **Ectopic Pregnancy** until proven otherwise. **1. Why Ectopic Pregnancy is correct:** * **Amenorrhea (8 weeks):** Suggests a pregnancy-related condition. * **Thick Endometrium:** In an ectopic pregnancy, the endometrium undergoes a **decidual reaction** due to progesterone production from the corpus luteum, despite the embryo being implanted outside the uterus. * **Lateral Adnexal Mass:** This represents the gestational sac or a hematoma (if leaking) within the fallopian tube (the most common site, specifically the **ampulla**). **2. Why the other options are incorrect:** * **Torsion of Dermoid Cyst:** While it presents with acute pain and an adnexal mass, it is usually not associated with amenorrhea or a thickened endometrium. * **Tubo-ovarian Mass:** Typically follows Pelvic Inflammatory Disease (PID). It presents with fever, vaginal discharge, and chronic pain rather than acute amenorrhea. * **Hydrosalpinx:** This is a chronic collection of fluid in the fallopian tube. It is usually asymptomatic or causes chronic dull pain and is not associated with amenorrhea. **3. NEET-PG High-Yield Pearls:** * **Gold Standard Diagnosis:** Transvaginal Ultrasound (TVS) + Serial β-hCG levels. * **Arias-Stella Reaction:** A characteristic histological change in the endometrium (hypersecretory glands with nuclear pleomorphism) seen in ectopic pregnancy. * **Discriminatory Zone:** The level of β-hCG (usually 1500–2000 mIU/mL) at which a gestational sac should be visible on TVS. If not seen, suspect ectopic pregnancy. * **Most Common Site:** Ampulla of the Fallopian tube. * **Most Common Site for Rupture:** Isthmus (due to its narrow lumen).

Q: Which among the following is the most common chromosomal anomaly encountered in spontaneously aborted fetuses?

Trisomy 16. **Explanation:** Chromosomal abnormalities are the leading cause of spontaneous abortions, accounting for approximately 50–60% of first-trimester miscarriages. Among these, **Autosomal Trisomies** are the most frequent category (approx. 50% of all abnormal cases). **Why Trisomy 16 is the correct answer:** While Trisomy 21 is the most common trisomy seen in live births, **Trisomy 16** is the most common trisomy encountered in spontaneous abortions. It is considered lethal in its non-mosaic form and is virtually never seen in live-born infants. It accounts for nearly one-third of all trisomic abortions. **Analysis of Incorrect Options:** * **Trisomy 13 (Patau Syndrome) & Trisomy 18 (Edwards Syndrome):** While these are common autosomal trisomies that lead to significant phenotypic abnormalities and high rates of intrauterine fetal death, their individual prevalence in early miscarriages is significantly lower than that of Trisomy 16. * **Trisomy 21 (Down Syndrome):** This is the most common trisomy among **live births** because it has a higher survival rate in utero compared to other trisomies. However, in the context of early spontaneous abortions, it is less frequent than Trisomy 16. **NEET-PG High-Yield Pearls:** 1. **Most common single chromosomal anomaly:** Turner Syndrome (45,X) — *Note: While Trisomy 16 is the most common trisomy, 45,X is the most common specific karyotype.* 2. **Most common class of anomaly:** Autosomal Trisomy. 3. **Triploidy:** Often associated with partial hydatidiform moles. 4. **Recurrent Pregnancy Loss (RPL):** The most common parental chromosomal anomaly is a **Balanced Reciprocal Translocation**.

Q: Which of the following is the earliest sign of magnesium toxicity in a patient with eclampsia on treatment with magnesium sulphate?

Loss of deep tendon reflexes. Magnesium sulphate ($MgSO_4$) is the drug of choice for controlling and preventing seizures in eclampsia. It acts as a CNS depressant and neuromuscular blocker by inhibiting acetylcholine release at the motor endplate. However, it has a narrow therapeutic index, making monitoring of clinical signs essential. **Explanation of the Correct Answer:** * **A. Loss of deep tendon reflexes (Patellar reflex):** This is the **earliest clinical sign** of magnesium toxicity. It occurs at serum magnesium levels of **7–10 mEq/L**. The loss of the knee-jerk reflex serves as a "warning signal" that magnesium levels are rising toward dangerous thresholds, allowing for intervention before life-threatening complications occur. **Explanation of Incorrect Options:** * **B. Respiratory depression:** This is a late sign of toxicity, typically occurring when serum levels reach **11–15 mEq/L**. It results from the paralysis of respiratory muscles. * **C. Cardiac arrest:** This is the terminal event of magnesium toxicity, occurring at very high levels, usually **>15 mEq/L**, due to the direct effect of magnesium on the cardiac conduction system. * **D. Decreased urine output:** While oliguria is a **predisposing factor** for toxicity (as magnesium is excreted solely by the kidneys), it is not a sign of toxicity itself. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Range:** 4–7 mEq/L. * **Monitoring Parameters:** Before every dose, ensure: 1) Patellar reflex is present, 2) Respiratory rate >12–14/min, and 3) Urine output >30 ml/hr (or >100 ml in 4 hours). * **Antidote:** 10 ml of **10% Calcium Gluconate** IV (administered slowly over 10 minutes).

Q: Low maternal serum 25-hydroxyvitamin D is associated with all of the following pregnancy and neonatal outcomes, EXCEPT:

Caesarian Section. **Explanation:** Vitamin D (25-hydroxyvitamin D) plays a crucial role in pregnancy, acting as a potent immunomodulator and regulator of glucose metabolism and placental development. **Why Caesarean Section is the Correct Answer:** While early observational studies suggested a link between Vitamin D deficiency and increased rates of primary C-sections (theoretically due to impaired pelvic muscle strength), large-scale meta-analyses and Cochrane reviews have **not** consistently demonstrated a statistically significant association. Therefore, C-section is not considered a definitive outcome of low maternal Vitamin D levels in current evidence-based guidelines. **Analysis of Incorrect Options:** * **Gestational Diabetes (GDM):** Vitamin D influences insulin secretion and sensitivity. Low levels are associated with increased insulin resistance and a higher risk of GDM. * **Pre-eclampsia:** Vitamin D modulates the renin-angiotensin system and promotes healthy placental angiogenesis. Deficiency is linked to endothelial dysfunction and an increased risk of hypertensive disorders of pregnancy. * **Small for Gestational Age (SGA):** Vitamin D is vital for optimal placental function and fetal bone mineralization. Low levels are associated with restricted fetal growth and lower birth weights. **NEET-PG High-Yield Pearls:** * **Active Form:** 1,25-dihydroxyvitamin D3 (Calcitriol). * **Storage Form:** 25-hydroxyvitamin D (Calcidiol) – this is the form measured to assess status. * **Fetal Source:** The fetus depends entirely on maternal transfer of 25(OH)D across the placenta. * **Neonatal Impact:** Severe maternal deficiency can lead to neonatal hypocalcemia, tetany, and congenital rickets.

Q: Which is the earliest ectopic pregnancy location to undergo rupture?

Isthmic. **Explanation:** The timing of rupture in an ectopic pregnancy is primarily determined by the **distensibility and diameter** of the anatomical site where the blastocyst implants. **Why Isthmic is the correct answer:** The **isthmus** is the narrowest part of the fallopian tube with a very thin muscular wall and minimal distensibility. Because the lumen is so constricted, the growing embryo quickly outgrows the available space and erodes through the wall. Consequently, isthmic pregnancies undergo the **earliest rupture**, typically between **6 to 8 weeks** of gestation. **Analysis of Incorrect Options:** * **Ampullary:** This is the most common site of ectopic pregnancy (70-80%). The ampulla is wider and more distensible than the isthmus, allowing the pregnancy to progress further. Rupture usually occurs later, around **8 to 12 weeks**. * **Interstitial:** This is the portion of the tube that traverses the thick myometrium of the uterus. Due to the surrounding muscular support and rich blood supply, it can expand significantly. Rupture occurs **latest (12–16 weeks)** but is the most life-threatening due to massive hemorrhage from the uterine arteries. * **Ovarian:** These are rare and do not follow a fixed timeline for rupture as strictly as tubal pregnancies, though they generally occur earlier than interstitial ones. **NEET-PG High-Yield Pearls:** * **Most common site of ectopic:** Ampulla. * **Earliest rupture:** Isthmus (6-8 weeks). * **Latest rupture/Most dangerous:** Interstitial (12-16 weeks). * **Most common site for Ectopic following IVF:** Interstitial. * **Classic Triad:** Amenorrhea, abdominal pain, and vaginal bleeding (present in only 50% of cases).

Q: A 35 weeks pregnant woman has ultrasound parameters corresponding to gestational age. Doppler shows absent end diastolic flow. What is the recommended management?

Plan for termination. **Explanation:** The core issue in this scenario is **Absent End Diastolic Flow (AEDF)** in the umbilical artery, which signifies high placental resistance and impending fetal compromise. **1. Why "Plan for termination" is correct:** According to standard management protocols for Fetal Growth Restriction (FGR) and placental insufficiency, the presence of AEDF at **≥34 weeks** of gestation is a definitive indication for delivery. At 35 weeks, the risks of intrauterine fetal demise (IUFD) due to chronic hypoxia outweigh the risks of prematurity. Therefore, the pregnancy should be terminated (delivered), usually via Cesarean section if the Bishop score is unfavorable or fetal distress is evident. **2. Why the other options are incorrect:** * **Options A & B:** Monitoring until 37 weeks or until the flow reverses is dangerous. AEDF is a late-stage marker; waiting further increases the risk of acidosis and stillbirth. Expectant management is only considered if the fetus is <34 weeks to gain maturity, but even then, it requires intensive monitoring. * **Option C:** While steroids (Betamethasone/Dexamethasone) are administered for fetal lung maturity if delivery is planned between 24 and 36+6 weeks, the question asks for the "management" of the pregnancy. "Waiting for 48 hours" is secondary to the primary decision to terminate. In practice, steroids are given *while* preparing for delivery, but the definitive management plan is termination. **Clinical Pearls for NEET-PG:** * **S/D Ratio:** The first Doppler sign of placental insufficiency is an increased Systolic/Diastolic ratio. * **AEDF:** Delivery is indicated at **≥34 weeks**. * **REDF (Reversed End Diastolic Flow):** This is a critical emergency. Delivery is indicated at **≥30-32 weeks**. * **Ductus Venosus:** Abnormal flow (absent/reversed a-wave) in the ductus venosus is the most sensitive predictor of imminent fetal death.

Q: Among the following, which is the most sensitive ultrasonographic finding of Trisomy 21?

Thickened nuchal fold. **Explanation:** The detection of Trisomy 21 (Down Syndrome) via ultrasonography relies on identifying specific "soft markers." Among the options provided, **Thickened Nuchal Fold (NF)** is the most sensitive and specific second-trimester marker. 1. **Why Thickened Nuchal Fold is Correct:** Measured between 15 and 20 weeks of gestation, a nuchal fold thickness of **≥6 mm** is considered abnormal. It has the highest positive likelihood ratio (LR) for Trisomy 21 in the second trimester. Unlike the nuchal translucency (NT) seen in the first trimester, the nuchal fold persists longer and is a highly reliable indicator of lymphatic obstruction or cardiovascular congestion associated with Down Syndrome. 2. **Analysis of Incorrect Options:** * **Absent Nasal Bone:** While a very strong marker (high specificity), it is less sensitive than the nuchal fold in the second trimester because the nasal bone may simply be late to ossify or difficult to visualize depending on fetal position. * **Short Femur:** This is a common finding in many skeletal dysplasias and growth restrictions; its sensitivity for Trisomy 21 is lower compared to nuchal thickening. * **Echogenic Bowel:** While associated with Trisomy 21, it is also frequently seen in cystic fibrosis, intra-amniotic hemorrhage, and congenital infections (CMV), making it less specific and sensitive for Down Syndrome alone. **High-Yield Clinical Pearls for NEET-PG:** * **First Trimester Screen:** Increased **Nuchal Translucency (NT)** + Low PAPP-A + High β-hCG. * **Second Trimester Screen (Quadruple Test):** Low AFP, Low Estriol (uE3), High hCG, and High Inhibin-A. * **Most common cardiac defect:** Endocardial cushion defect (Atrioventricular Septal Defect). * **Most sensitive 2nd-trimester USG marker:** Nuchal Fold thickness (≥6 mm).

Question 1

A small-sized placenta is typically seen in which of the following conditions?

Accepted Answer

Pre-eclampsia

Answer

Peripheral vascular disease in the mother

Answer

Maternal weight less than 50 kg

Answer

Multiple pregnancy

Question 2

Which of the following is NOT considered a high-risk pregnancy factor?

Accepted Answer

Vertex presentation

Answer

Elderly primigravida

Answer

Short stature primigravida

Answer

Diabetes

Question 3

A female presents with 8 weeks of amenorrhea and left lower abdominal pain. Ultrasonography reveals a thick endometrium with a mass in the lateral adnexa. What is the most probable diagnosis?

Accepted Answer

Ectopic pregnancy

Answer

Torsion of dermoid cyst

Answer

Tubo-ovarian mass

Answer

Hydrosalpinx

Question 4

Which among the following is the most common chromosomal anomaly encountered in spontaneously aborted fetuses?

Accepted Answer

Trisomy 16

Answer

Trisomy 13

Answer

Trisomy 18

Answer

Trisomy 21

Question 5

Which of the following is the earliest sign of magnesium toxicity in a patient with eclampsia on treatment with magnesium sulphate?

Accepted Answer

Loss of deep tendon reflexes

Answer

Respiratory depression

Answer

Cardiac arrest

Answer

Decreased urine output

Question 6

Low maternal serum 25-hydroxyvitamin D is associated with all of the following pregnancy and neonatal outcomes, EXCEPT:

Accepted Answer

Caesarian Section

Answer

Gestational Diabetes

Answer

Pre-eclampsia

Answer

Small for Gestational Age Neonate

Question 7

A couple with an Rh-positive female and an Rh-negative male seeks counseling regarding pregnancy. What is the recommended course of action?

Accepted Answer

No treatment is needed.

Answer

Administer vaccine to the mother after the birth of the first baby.

Answer

Administer vaccine to the first baby.

Answer

Administer vaccine to the father.

Question 8

Which is the earliest ectopic pregnancy location to undergo rupture?

Accepted Answer

Isthmic

Answer

Interstitial

Answer

Ampullary

Answer

Ovarian

Question 9

A 35 weeks pregnant woman has ultrasound parameters corresponding to gestational age. Doppler shows absent end diastolic flow. What is the recommended management?

Accepted Answer

Plan for termination

Answer

Monitor until end diastolic flow becomes reversed or until 37 weeks gestation

Answer

Monitor until 37 weeks gestation

Answer

Administer steroids and wait for 48 hours

Question 10

Among the following, which is the most sensitive ultrasonographic finding of Trisomy 21?

Accepted Answer

Thickened nuchal fold

Answer

Absent nasal bone

Answer

Short femur

Answer

Echogenic bowel

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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