Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 861: A fetomaternal transfusion of more than 30 ml has been found in what percentage of women at delivery?

A. Less than 1%
B. 5%
C. 10% (Correct Answer)
D. 15%

Explanation: **Explanation:** The correct answer is **10%**. **Understanding the Concept:** Fetomaternal hemorrhage (FMH) refers to the entry of fetal erythrocytes into the maternal circulation. While small amounts of FMH occur in nearly all pregnancies, the volume typically increases at delivery due to placental separation. Standard clinical practice involves administering a 300 µg dose of Anti-D immunoglobulin to Rh-negative women, which covers up to **30 ml of fetal whole blood** (or 15 ml of packed red cells). Large-scale studies have shown that approximately **10%** of women experience a transfusion exceeding 30 ml at the time of delivery. This is a high-yield statistic because it highlights why a routine "standard dose" of Anti-D may be insufficient for 1 in 10 women, necessitating screening tests like the Kleihauer-Betke (KB) test. **Analysis of Options:** * **A. Less than 1%:** This is incorrect. While massive FMH (>150 ml) occurs in less than 1% of cases, a 30 ml bleed is far more common. * **B. 5%:** This underestimates the prevalence found in obstetric populations. * **D. 15%:** This overestimates the frequency; 10% is the established benchmark in standard textbooks (e.g., Williams Obstetrics). **NEET-PG High-Yield Pearls:** * **Screening:** The **Rosette Test** is the initial qualitative screening test for FMH. * **Quantification:** The **Kleihauer-Betke (KB) Test** is the gold standard for quantifying FMH to calculate the required dose of Anti-D. * **Calculation Formula:** (Percent of fetal cells × 50) / 30 = Number of 300 µg vials required. * **Timing:** Anti-D should ideally be given within **72 hours** of the sensitizing event.

Question 862: What is the most common cause of intrauterine infection?

A. Rubella
B. Toxoplasma
C. Hepatitis
D. Cytomegalovirus (Correct Answer)

Explanation: **Explanation:** **Cytomegalovirus (CMV)** is the most common cause of congenital (intrauterine) infection worldwide, affecting approximately 0.2% to 2.2% of all live births. It belongs to the Herpesviridae family. The high prevalence is attributed to the fact that CMV can be transmitted to the fetus during both a **primary maternal infection** and a **recurrent/secondary infection** (reactivation or reinfection with a different strain), although the risk of transmission is significantly higher (30-40%) during a primary infection. **Analysis of Incorrect Options:** * **Rubella:** While a classic component of the TORCH complex, the incidence of Congenital Rubella Syndrome (CRS) has drastically declined in regions with robust MMR vaccination programs. It is now much less common than CMV. * **Toxoplasma:** Transmission of *Toxoplasma gondii* occurs via oocysts in cat feces or undercooked meat. While it causes serious fetal sequelae (the classic triad of chorioretinitis, hydrocephalus, and intracranial calcifications), its overall prevalence is lower than CMV. * **Hepatitis:** Hepatitis B and C are primarily transmitted **perinatally** (during delivery) or via breast milk, rather than causing true intrauterine/congenital infection syndromes. They do not typically cause structural malformations. **High-Yield Clinical Pearls for NEET-PG:** * **Most common clinical feature:** Most neonates (90%) are asymptomatic at birth. * **Most common sequela:** Sensorineural Hearing Loss (SNHL). CMV is the leading non-genetic cause of SNHL in children. * **Classic Imaging Finding:** **Periventricular calcifications** (distinguish from Toxoplasmosis, which presents with diffuse/scattered intracranial calcifications). * **Diagnosis:** Gold standard for fetal diagnosis is **Amniotic fluid PCR**. For neonates, detection of the virus in urine or saliva within the first 3 weeks of life is diagnostic.

Question 863: Abnormal alpha-fetoprotein levels are seen in which of the following conditions?

A. Trisomy 18
B. Twin pregnancy
C. Neural tube defect
D. All of the above (Correct Answer)

Explanation: **Explanation:** Alpha-fetoprotein (AFP) is a glycoprotein synthesized initially by the yolk sac and later by the fetal liver. It is the fetal equivalent of albumin. Maternal Serum Alpha-Fetoprotein (MSAFP) levels are a crucial screening tool used between 15–20 weeks of gestation to identify fetal anomalies. **Why "All of the above" is correct:** The term "abnormal" encompasses both **elevated** and **decreased** levels of AFP: * **Neural Tube Defects (NTDs):** Conditions like anencephaly and spina bifida involve a defect in the fetal skin/integument, allowing AFP to leak into the amniotic fluid and subsequently into the maternal circulation. This leads to **elevated MSAFP**. * **Twin Pregnancy:** Since AFP is produced by the fetus, multiple gestations result in a higher cumulative production of the protein, leading to **elevated MSAFP** (typically >2.5 MoM). * **Trisomy 18 (and Trisomy 21):** Chromosomal aneuploidies are characteristically associated with **decreased MSAFP** levels. In Trisomy 18 (Edwards Syndrome), AFP is low, along with low hCG and low estriol (Triple Screen). **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of abnormal MSAFP:** Incorrect gestational dating (underestimation or overestimation of pregnancy age). * **Causes of Elevated MSAFP:** NTDs, abdominal wall defects (Omphalocele, Gastroschisis), Multiple pregnancy, Renal anomalies (Finnish-type nephrosis), and Fetal demise. * **Causes of Decreased MSAFP:** Trisomy 21 (Down Syndrome), Trisomy 18, Molar pregnancy, and Maternal obesity. * **Standard Cut-off:** 2.5 Multiples of the Median (MoM) is generally used as the upper limit of normal.

Question 864: What happens to the S/D ratio in the umbilical artery during the progression of normal pregnancy?

A. Decreases (Correct Answer)
B. Increases
C. Plateaus
D. Shows no significant change

Explanation: **Explanation:** The **S/D ratio** (Systolic/Diastolic ratio) in the umbilical artery is a measure of placental vascular resistance. In a normal pregnancy, as the fetus grows, the placenta undergoes significant physiological changes, including the proliferation of tertiary villi and the widening of the vascular bed. **Why the correct answer (A) is right:** As pregnancy progresses, the **placental resistance decreases** to accommodate the increased blood flow required for fetal growth. This drop in resistance leads to a significant increase in the **end-diastolic flow (EDF)**. Since the denominator (Diastole) increases more proportionately than the numerator (Systole), the overall S/D ratio **decreases**. By the third trimester, a normal S/D ratio is typically less than 3.0. **Why the incorrect options are wrong:** * **B & C:** An **increase** or **plateau** in the S/D ratio indicates high placental resistance. This is pathological and is commonly seen in conditions like Preeclampsia or Fetal Growth Restriction (FGR). * **D:** The ratio must change to reflect the dynamic maturation of the placental unit; a lack of change would suggest a failure of the low-resistance circuit to develop. **High-Yield Clinical Pearls for NEET-PG:** 1. **Absent End-Diastolic Velocity (AEDV):** An ominous sign indicating high resistance; it is associated with a high risk of perinatal mortality. 2. **Reversed End-Diastolic Velocity (REDV):** The most severe form of abnormal Doppler; it indicates imminent fetal compromise and usually necessitates urgent delivery. 3. **Normal Values:** The S/D ratio is usually >3.0 before 30 weeks and **<3.0 after 30 weeks** of gestation.

Question 865: Undiagnosed or undetected ectopic pregnancy is a common cause of maternal death during the first trimester. What is the most valuable diagnostic test in a case of suspected ectopic pregnancy?

A. Serial human chorionic gonadotropin (hCG) levels
B. Transvaginal ultrasonography (USG) (Correct Answer)
C. Progesterone measurement
D. Culdocentesis

Explanation: **Explanation:** The diagnosis of ectopic pregnancy relies on the "Discriminatory Zone" concept—the level of hCG at which an intrauterine pregnancy (IUP) should be visible on ultrasound. **Why Transvaginal Ultrasonography (TVS) is the Correct Answer:** TVS is the **single most valuable diagnostic tool** because it can directly visualize an extrauterine gestational sac, an adnexal mass, or "free fluid" in the Pouch of Douglas. More importantly, the definitive identification of an **intrauterine** pregnancy via TVS effectively rules out ectopic pregnancy (except in rare heterotopic cases). TVS is superior to transabdominal USG as it can detect a gestational sac as early as 4.5–5 weeks. **Analysis of Incorrect Options:** * **Serial hCG levels:** While crucial for monitoring pregnancy viability, a single hCG value cannot diagnose an ectopic pregnancy. Serial levels help determine if a pregnancy is failing, but they do not provide anatomical localization. * **Progesterone measurement:** Low levels (<5 ng/mL) suggest a non-viable pregnancy but cannot distinguish between a miscarriage and an ectopic pregnancy. * **Culdocentesis:** Historically used to detect hemoperitoneum in ruptured ectopics, it is now considered obsolete due to the high sensitivity and non-invasive nature of TVS. **High-Yield Clinical Pearls for NEET-PG:** * **Discriminatory Zone:** For TVS, the hCG threshold is typically **1,500–2,000 mIU/mL**. If hCG is above this and the uterus is empty, ectopic pregnancy must be suspected. * **Classic Triad:** Amenorrhea, abdominal pain, and vaginal bleeding (present in only 50% of cases). * **Most common site:** Ampulla of the Fallopian tube. * **Gold Standard for Diagnosis:** Laparoscopy (allows for both definitive diagnosis and surgical management).

Question 866: A 35-year-old female with Gravida-2 and Parity 1+0 is suffering from hepatic encephalopathy. What is the likely cause?

A. Hepatitis B
B. Hepatitis E (Correct Answer)
C. Hepatitis D
D. Hepatitis A

Explanation: **Explanation:** **Hepatitis E Virus (HEV)** is the most common cause of acute viral hepatitis and hepatic encephalopathy in pregnant women, particularly in developing countries. While HEV is typically a self-limiting infection in the general population, it takes a fulminant course in pregnancy, especially during the **second and third trimesters**. The case describes a G2P1 patient (multigravida) with hepatic encephalopathy, which is a hallmark of Fulminant Hepatic Failure (FHF). * **Why Hepatitis E is Correct:** HEV is a water-borne RNA virus (Hepeviridae family). In pregnancy, the case fatality rate can reach as high as **15–25%**. The severity is attributed to high viral loads, altered maternal immune response (Th2 shift), and high levels of progesterone/estrogen which may enhance viral replication. * **Why Other Options are Incorrect:** * **Hepatitis A:** Also water-borne, but rarely causes fulminant failure or encephalopathy in pregnancy. * **Hepatitis B:** A DNA virus transmitted parenterally. While it can cause chronic liver disease and vertical transmission, it is less likely than HEV to cause acute encephalopathy in a pregnant patient unless there is a superinfection. * **Hepatitis D:** Requires co-infection with Hepatitis B to replicate; it is not the primary cause of epidemic-style fulminant hepatitis in pregnancy. **High-Yield NEET-PG Pearls:** * **Mode of Transmission:** Fecal-oral (contaminated water). * **Most common cause of jaundice in pregnancy:** Hepatitis E (globally). * **Vertical Transmission:** High rates of transplacental transmission are seen with HEV, often leading to neonatal hypoglycemia and jaundice. * **Prognosis:** If a pregnant woman develops HEV-induced FHF, the mortality is significantly higher than any other viral hepatitis.

Question 867: Expectant management of placenta previa includes all of the following except?

A. Anti-D immunoglobulin
B. Cervical cerclage (Correct Answer)
C. Blood transfusion
D. Steroids

Explanation: **Explanation:** The expectant management of placenta previa (also known as **MacAfee and Johnson’s protocol**) aims to prolong the pregnancy until fetal lung maturity is achieved, provided the mother and fetus remain stable. **Why Cervical Cerclage is the Correct Answer:** Cervical cerclage is a surgical procedure used to treat cervical insufficiency. In the context of placenta previa, it is **not** a standard component of expectant management. Performing a cerclage or any vaginal/cervical manipulation in a patient with placenta previa is contraindicated as it can trigger massive, life-threatening hemorrhage by disturbing the placental site. **Analysis of Incorrect Options:** * **Anti-D Immunoglobulin:** Essential for all Rh-negative unsensitized mothers experiencing vaginal bleeding (antepartum hemorrhage) to prevent isoimmunization. * **Blood Transfusion:** A cornerstone of management. The goal is to maintain maternal hemoglobin levels (ideally >10 g/dL) to ensure hemodynamic stability in case of sudden, recurrent bleeding. * **Steroids:** Administered (e.g., Betamethasone or Dexamethasone) between 24 and 34 weeks of gestation to accelerate fetal lung maturity, reducing the risk of Respiratory Distress Syndrome (RDS) if preterm delivery becomes necessary. **High-Yield Clinical Pearls for NEET-PG:** * **MacAfee Protocol Criteria:** Pregnancy <37 weeks, bleeding is not life-threatening, and the fetus is alive and stable. * **Contraindication:** **Vaginal examination (PV)** is strictly contraindicated in placenta previa unless performed in an "Operation Theatre" setting (Double Setup Examination). * **Investigation of Choice:** Transvaginal Sonography (TVS) is the gold standard for diagnosing the exact location of the placenta (safe when performed by experts). * **Delivery Timing:** In stable cases, elective delivery is usually planned at **37 weeks**.

Question 868: A 29-year-old primigravida at 36 weeks gestation with Rh-negative blood type presents with vaginal bleeding and a history of abdominal trauma. Which of the following tests is advised to estimate the size of fetomaternal hemorrhage?

A. Rosette test
B. Kleihauer acid elution test (Correct Answer)
C. Indirect Coombs test
D. Middle cerebral artery peak systolic velocity

Explanation: **Explanation:** In an Rh-negative mother, abdominal trauma can cause **Fetomaternal Hemorrhage (FMH)**, leading to isoimmunization. To prevent this, Anti-D immunoglobulin must be administered. While a standard dose (300 mcg) covers up to 30 mL of fetal whole blood, the **Kleihauer-Betke (KB) test** is required to quantify larger bleeds and calculate the exact dose of Anti-D needed. * **Why Option B is Correct:** The Kleihauer-Betke test is based on the principle that **Fetal Hemoglobin (HbF)** is resistant to acid elution, whereas adult hemoglobin (HbA) is not. When a maternal blood smear is treated with acid, adult cells become "ghost cells," while fetal RBCs remain dark pink. This allows for the **quantification** of fetal cells to estimate the volume of hemorrhage. * **Why Other Options are Incorrect:** * **A. Rosette Test:** This is a **qualitative** (screening) test. It detects the presence of fetal cells but cannot quantify the volume of the bleed. If positive, it must be followed by a KB test. * **C. Indirect Coombs Test (ICT):** This detects maternal antibodies against Rh antigens. It is used for screening sensitization, not for quantifying an acute bleed. * **D. MCA-PSV:** This Doppler ultrasound parameter is the gold standard for detecting **fetal anemia**, not for quantifying the volume of maternal-fetal hemorrhage. **High-Yield Clinical Pearls for NEET-PG:** * **Formula for Anti-D dose:** (Volume of fetal bleed in mL / 30) + 1 (safety factor). * **Timing:** Anti-D should ideally be given within **72 hours** of the sensitizing event. * **Flow Cytometry:** This is an automated alternative to the KB test, offering better precision and less inter-observer variation.

Question 869: Which of the following infections, if occurs in the first trimester, leads to the maximum incidence of congenital malformations?

A. Rubella (Correct Answer)
B. Toxoplasmosis
C. Cytomegalovirus (CMV)
D. All of the above

Explanation: **Explanation:** The correct answer is **Rubella**. The incidence of congenital malformations following maternal infection is highly dependent on the gestational age at the time of exposure. **1. Why Rubella is Correct:** Rubella is the most teratogenic of the TORCH infections when contracted in the **first trimester**. If maternal infection occurs before 11 weeks of gestation, the risk of congenital rubella syndrome (CRS) is as high as **80–90%**. The virus causes chronic infection of the developing fetus, leading to classic malformations known as Gregg’s Triad: Sensorineural deafness (most common), Congenital cataracts, and Cardiac defects (Patent Ductus Arteriosus). **2. Why Other Options are Incorrect:** * **Toxoplasmosis:** While the *severity* of fetal damage is highest in the first trimester, the *incidence* of transmission is lowest (approx. 10–15%). Transmission rates increase as pregnancy progresses, peaking in the third trimester. * **Cytomegalovirus (CMV):** CMV is the most common cause of congenital infection overall; however, it does not match Rubella's high rate of structural malformations specifically in the first trimester. Most CMV-infected neonates are asymptomatic at birth. **3. NEET-PG High-Yield Pearls:** * **Rule of Thumb:** For most TORCH infections, **severity** is highest in the 1st trimester, but **transmission rate** is highest in the 3rd trimester. * **Rubella Exception:** It is unique because both the risk of transmission and the risk of malformation are highest in the first trimester. * **Vaccination:** Rubella is a live-attenuated vaccine (MMR); it must be given in the postpartum period or at least 1 month before conception. It is contraindicated during pregnancy. * **Diagnosis:** The presence of **IgM** antibodies in fetal blood or neonatal cord blood confirms congenital infection.

Question 870: In a pregnant woman of 28 weeks gestation, IUD is earliest demonstrated on X-ray by:

A. Increased flexion
B. Overlapping of cranial bones
C. Spalding's sign
D. Gas in vessels (Correct Answer)

Explanation: **Explanation:** Intrauterine Death (IUD) leads to characteristic radiological signs, but their timing of appearance varies significantly. **1. Why "Gas in vessels" is correct:** The appearance of gas in the fetal large vessels (aorta) or heart is known as **Robert’s Sign**. It is the **earliest** radiological sign of IUD, appearing as early as **6 to 12 hours** after fetal death. The gas (primarily nitrogen) is released from fetal blood due to decomposition and is visible on an X-ray long before skeletal changes occur. **2. Analysis of Incorrect Options:** * **Spalding’s Sign (Overlapping of cranial bones):** This is a classic sign of IUD but typically takes **4 to 7 days** to develop. It occurs due to the liquefaction of the brain and loss of intracranial pressure, leading to the collapse of the skull bones. * **Increased Flexion (Deuel’s Halo Sign/Curvature of Spine):** Loss of fetal muscle tone leads to an exaggerated "c-shaped" flexion of the spine. Like Spalding's sign, this is a late feature appearing several days after death. * **Overlapping of cranial bones:** This is simply the description of Spalding's sign (Option C), which is not the earliest sign. **Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** Today, **Ultrasonography (USG)** is the investigation of choice for IUD. The earliest sign on USG is the **absence of fetal heart activity**. * **Robert’s Sign:** Earliest X-ray sign (12 hours). * **Spalding’s Sign:** Most common X-ray sign (4–7 days). * **Deuel’s Halo Sign:** Edema of the fetal scalp causing a "halo" appearance on X-ray (occurs within 48 hours). * **Note:** X-rays are now obsolete in modern obstetrics for diagnosing IUD due to radiation risks and the superior accuracy of USG.

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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