Maternal-Fetal Medicine Practice Questions

Q: All are true regarding symmetric IUGR except?

Obstetric cause like utero-placental insufficiency. **Explanation:** Intrauterine Growth Restriction (IUGR) is classified into two types: **Symmetric (Type I)** and **Asymmetric (Type II)**. Understanding the distinction is high-yield for NEET-PG. **Why Option A is the correct answer (The False Statement):** Symmetric IUGR is typically caused by **intrinsic factors** that affect the fetus from early pregnancy, such as chromosomal abnormalities (e.g., Trisomies), intrauterine infections (TORCH), or severe maternal malnutrition. In contrast, **utero-placental insufficiency** is the hallmark cause of **Asymmetric IUGR**, where growth slows down later in pregnancy (third trimester) due to a lack of nutrients. **Analysis of other options:** * **Option B (Ponderal Index > 2):** In symmetric IUGR, both weight and length are proportionately reduced. Therefore, the Ponderal Index (Weight/Length³) remains **normal (>2)**. In asymmetric IUGR, the fetus is "wasted," leading to a low Ponderal Index (<2). * **Option C (First Trimester):** Symmetric IUGR results from an insult during the **hyperplastic phase** of cellular growth (early pregnancy), leading to a decrease in the total number of cells. * **Option D (Brain growth spared):** This is a characteristic of **Asymmetric IUGR** (Brain-sparing effect). In **Symmetric IUGR**, there is no brain-sparing; the head circumference, abdominal circumference, and femur length are all proportionately small. **Clinical Pearls for NEET-PG:** * **Symmetric IUGR:** Early onset, decreased cell *number*, normal HC/AC ratio, Ponderal Index >2, poor prognosis. * **Asymmetric IUGR:** Late onset (3rd trimester), decreased cell *size*, increased HC/AC ratio (Head > Abdomen), Ponderal Index <2, better prognosis with postnatal catch-up growth. * **Most common cause of IUGR overall:** Utero-placental insufficiency (Asymmetric).

Q: Fetal blood loss in abnormal cord insertion is seen in which of the following conditions?

Vasa previa. **Explanation:** **Vasa previa** is the correct answer because it involves fetal vessels running through the membranes, unprotected by placental tissue or the umbilical cord (Wharton’s jelly), across the internal os. This condition is most commonly associated with **velamentous insertion of the cord** or a **succenturiate lobe**. When the membranes rupture (spontaneously or artificially), these exposed fetal vessels are easily lacerated, leading to rapid fetal exsanguination. Since the blood lost is entirely fetal, even a small amount can lead to fetal distress and death. **Incorrect Options:** * **Decidua basalis:** This is the maternal component of the placenta. Bleeding here is maternal in origin, typically seen in placental abruption. * **Battledore placenta (Marginal insertion):** The cord inserts at the margin of the placenta rather than the center. While it increases the risk of preterm labor, it rarely causes fetal vessel rupture or significant fetal blood loss. * **Succenturiate placenta:** This refers to an accessory lobe. While it is a *risk factor* for vasa previa (if the connecting vessels cross the os), the presence of the lobe itself does not imply fetal blood loss unless vasa previa is concurrently present. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Rupture of membranes + Painless vaginal bleeding + Fetal bradycardia/distress. * **Diagnosis:** Antenatally via **Transvaginal Color Doppler** (Gold Standard). * **Apt Test / Ogita Test:** Used to differentiate fetal hemoglobin from maternal hemoglobin in vaginal blood. * **Management:** If diagnosed prenatally, elective Cesarean section is planned at 34–35 weeks to avoid labor and membrane rupture.

Q: What is the dose of Anti-D immunoglobulin given to an Rh-negative patient with ectopic pregnancy in the first trimester?

50mcg. **Explanation:** The correct answer is **50 mcg (Option D)**. Rh-isoimmunization occurs when an Rh-negative mother is exposed to Rh-positive fetal red blood cells, leading to the production of anti-D antibodies. In the first trimester (up to 12–13 weeks), the total fetal blood volume is very small. Therefore, a "mini-dose" of **50 mcg** of Anti-D immunoglobulin is sufficient to neutralize the potential feto-maternal hemorrhage (FMH) associated with conditions like ectopic pregnancy, threatened abortion, or induced abortion. **Analysis of Options:** * **10 mcg, 25 mcg, 40 mcg (Options A, B, C):** These doses are sub-therapeutic and do not follow standard clinical guidelines (ACOG/RCOG/FOGSI) for the prevention of Rh-sensitization. * **50 mcg (Option D):** This is the standard "mini-dose" recommended for first-trimester sensitizing events. It can neutralize up to 2.5–5 ml of Rh-positive whole blood. **High-Yield Clinical Pearls for NEET-PG:** * **Standard Dose:** After 12 weeks of gestation or following full-term delivery, the standard dose is **300 mcg**, which neutralizes **30 ml** of fetal whole blood (or 15 ml of packed RBCs). * **Timing:** Anti-D should ideally be administered within **72 hours** of the sensitizing event. * **Kleihauer-Betke (KB) Test:** Used to quantify the volume of FMH to determine if additional doses of Anti-D are required beyond the standard 300 mcg in the third trimester or postpartum. * **Routine Prophylaxis:** In an unsensitized Rh-negative woman, 300 mcg is routinely given at **28 weeks** of gestation.

Q: Antenatal corticosteroids to reduce neonatal respiratory distress syndrome is most effective:

When given between 28 and 34 weeks of gestation. **Explanation:** The primary goal of antenatal corticosteroids (ACS) is to accelerate fetal lung maturity by stimulating the production of surfactant by Type II pneumocytes. **Why Option A is correct:** The maximum benefit of ACS in reducing the incidence and severity of Respiratory Distress Syndrome (RDS), Intraventricular Hemorrhage (IVH), and Necrotizing Enterocolitis (NEC) is seen when administered between **24 and 34 weeks** of gestation. While the question specifies 28–34 weeks, this remains the most effective window as the fetal lungs are in the saccular stage of development and highly responsive to steroids. **Why other options are incorrect:** * **Option B:** Weekly administration (serial courses) is contraindicated. It does not provide additional respiratory benefit and is associated with decreased birth weight and reduced head circumference. * **Option C:** While the maximum effect occurs if delivery happens between 24 hours and 7 days after the first dose, "within 48 hours" is too narrow a window. The treatment is most effective when the full course is completed at least 24 hours before delivery. * **Option D:** Before 24–26 weeks (pre-viable or periviable period), the lungs are in the canalicular stage with minimal surfactant-producing capacity, making steroids less effective, though they are still considered from 23 weeks in certain guidelines. **NEET-PG High-Yield Pearls:** * **Standard Regimen:** Betamethasone (12 mg IM, 2 doses, 24 hours apart) or Dexamethasone (6 mg IM, 4 doses, 12 hours apart). * **Betamethasone** is generally preferred due to better reduction in IVH. * **Rescue Dose:** A single repeat course can be given if the initial course was >7 days ago and the gestational age is <34 weeks. * **Late Preterm:** Recent guidelines (ACOG) now suggest considering ACS up to **36 weeks 6 days** in women at high risk of imminent preterm birth who have not received a prior course.

Q: Golden coloured amniotic fluid is typically seen in which of the following conditions?

Rh incompatibility. **Explanation:** The color of amniotic fluid is a significant clinical indicator of fetal well-being. **Golden-colored amniotic fluid** is a classic diagnostic sign of **Rh isoimmunization (Rh incompatibility)**. **1. Why Rh Incompatibility is correct:** In Rh isoimmunization, maternal antibodies cross the placenta and cause hemolysis of fetal red blood cells. This massive breakdown of hemoglobin leads to the production of **unconjugated bilirubin**. This bilirubin is excreted into the fetal urine and subsequently into the amniotic fluid, imparting a characteristic golden-yellow hue. **2. Why other options are incorrect:** * **Fetal death (Option B):** In cases of Intrauterine Fetal Death (IUFD), the amniotic fluid typically appears **dark brown or "tobacco juice"** colored due to the presence of decomposed blood and macerated fetal tissues. * **Intrauterine Growth Restriction (Option C):** Simple IUGR does not typically change the color of the fluid unless accompanied by distress. * **Fetal distress with IUGR (Option D):** Fetal distress leads to the passage of meconium. This results in **greenish** amniotic fluid (meconium-stained). If the meconium is old, it may appear greenish-yellow (saffron). **Clinical Pearls for NEET-PG:** * **Normal:** Colorless or pale straw-colored (near term). * **Green (Meconium):** Fetal distress (acute). * **Golden:** Rh incompatibility (due to bilirubin). * **Greenish-Yellow (Saffron):** Post-maturity. * **Dark Red/Port Wine:** Abruptio placentae (due to concealed hemorrhage). * **Dark Brown (Tobacco juice):** I.U.F.D.

Q: What is the commonest chromosomal abnormality in early spontaneous abortions?

Autosomal trisomy. **Explanation:** Chromosomal abnormalities are responsible for approximately 50–60% of first-trimester spontaneous abortions. Among these, numerical aberrations are the most frequent cause. **1. Why Autosomal Trisomy is Correct:** Autosomal trisomy is the **single most common** chromosomal abnormality found in early miscarriages, accounting for about **50%** of all chromosomally abnormal abortuses. It occurs due to non-disjunction during meiosis (usually maternal). * **Trisomy 16** is the most common specific trisomy identified in these cases (though it is never seen in live births). * **Trisomy 21, 18, and 13** are also frequent but have higher rates of survival to term compared to Trisomy 16. **2. Analysis of Incorrect Options:** * **Monosomy (Option A):** Specifically, **45,X (Turner Syndrome)** is the **single most common specific chromosomal pattern** (karyotype) found in spontaneous abortions (approx. 20%). However, as a *group*, autosomal trisomies are more common than monosomies. * **Triploidy (Option C):** This involves 69 chromosomes (often due to dispermy). It accounts for about 15% of cases and is frequently associated with hydatidiform changes (Partial Mole). * **Tetraploidy (Option D):** This involves 92 chromosomes. It is rare (approx. 5%) and usually results in very early pregnancy loss (blighted ovum). **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of 1st-trimester abortion:** Chromosomal abnormalities. * **Most common group of abnormalities:** Autosomal Trisomy. * **Most common specific Trisomy:** Trisomy 16. * **Most common specific Karyotype:** 45,X (Turner Syndrome). * **Most common cause of 2nd-trimester abortion:** Maternal factors (e.g., Cervical incompetence, uterine anomalies).

Q: Elevated acetylcholinesterase levels in amniotic fluid most likely indicate which of the following conditions?

Open neural tube defects. **Explanation:** The correct answer is **Open neural tube defects (ONTDs)**. **1. Why it is correct:** Acetylcholinesterase (AChE) is an enzyme primarily found in nervous tissue. In cases of open neural tube defects (such as anencephaly or open spina bifida), the fetal neural tissue is directly exposed to the amniotic fluid. This allows AChE to leak from the exposed cerebrospinal fluid and neural membranes into the amniotic sac. While Alpha-fetoprotein (AFP) is used as a screening tool, it can be elevated in various other conditions (e.g., abdominal wall defects). **Amniotic fluid AChE is highly specific** and serves as the confirmatory biochemical test for ONTDs following an elevated AFP. **2. Why other options are incorrect:** * **Oesophageal atresia:** This condition is associated with polyhydramnios (due to inability to swallow) and may show elevated AFP, but it does not involve exposed neural tissue; therefore, AChE levels remain normal. * **Down syndrome (Trisomy 21):** This is characterized by **decreased** maternal serum AFP and specific ultrasound markers (increased nuchal translucency). AChE is not a marker for chromosomal aneuploidies. * **Edward syndrome (Trisomy 18):** Similar to Down syndrome, this is associated with low maternal serum AFP and HCG levels. It does not typically cause elevated amniotic AChE. **Clinical Pearls for NEET-PG:** * **Sequence of Testing:** Maternal Serum AFP (Screening) → Ultrasound → Amniotic Fluid AFP → **Amniotic Fluid AChE (Confirmatory)**. * **False Positives:** If the amniotic fluid sample is contaminated with fetal blood, AChE can be falsely elevated (pseudocholinesterase). * **Closed NTDs:** Conditions like *spina bifida occulta* do not typically show elevated AFP or AChE because the defect is covered by skin.

Question 1

All are true regarding symmetric IUGR except?

Accepted Answer

Obstetric cause like utero-placental insufficiency

Answer

Ponderal index > 2

Answer

Problem occurring in first trimester

Answer

Brain growth (head circumference) spared

Question 2

Fetal blood loss in abnormal cord insertion is seen in which of the following conditions?

Accepted Answer

Vasa previa

Answer

Decidua basalis

Answer

Battledore placenta

Answer

Succenturiate placenta

Question 3

What is the dose of Anti-D immunoglobulin given to an Rh-negative patient with ectopic pregnancy in the first trimester?

Accepted Answer

50mcg

Answer

10mcg

Answer

25mcg

Answer

40mcg

Question 4

Antenatal corticosteroids to reduce neonatal respiratory distress syndrome is most effective:

Accepted Answer

When given between 28 and 34 weeks of gestation

Answer

When given every week

Answer

When given within 48 hours of delivery

Answer

When given less than 28 weeks of gestation

Question 5

Golden coloured amniotic fluid is typically seen in which of the following conditions?

Accepted Answer

Rh incompatibility

Answer

Fetal death

Answer

Intrauterine Growth Restriction (IUGR)

Answer

Fetal distress with IUGR

Question 6

Placenta previa is characterized by all of the following except?

Accepted Answer

Presents after the first trimester

Answer

Painless bleeding

Answer

Causeless bleeding

Answer

Recurrent bleeding

Question 7

What is the commonest chromosomal abnormality in early spontaneous abortions?

Accepted Answer

Autosomal trisomy

Answer

Monosomy

Answer

Triploidy

Answer

Tetraploidy

Question 8

Elevated acetylcholinesterase levels in amniotic fluid most likely indicate which of the following conditions?

Accepted Answer

Open neural tube defects

Answer

Oesophageal atresia

Answer

Down syndrome

Answer

Edward syndrome

Question 9

Kamla Rani, a 20-year-old female with mitral stenosis class II and rheumatic heart disease, becomes pregnant. Which intervention is NOT indicated in her management during labor?

Accepted Answer

Give Methergin at delivery of the anterior shoulder.

Answer

Give prophylactic antibiotics.

Answer

Apply outlet forceps in the second stage of labor.

Answer

Give iv furosemide at delivery of the placenta.

Question 10

Which of the following is NOT true regarding lupus and pregnancy?

Accepted Answer

Antibodies to ss-A and ss-B antigens can result in ventricular apical fibrosis in the neonate.

Answer

Lupus in pregnancy can result in renal failure.

Answer

Women with cutaneous lupus usually have no adverse pregnancy outcomes.

Answer

Lupus in pregnancy can result in preterm labor.

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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