Maternal-Fetal Medicine Practice Questions

Q: The fetus, which is foreign to the mother, is not rejected due to which of the following reasons?

All of the above. The survival of the fetus (a semi-allograft) within the maternal environment is a phenomenon known as **immunological privilege**. This is achieved through a multi-factorial mechanism involving anatomical, hormonal, and cellular barriers. ### **Explanation of Options:** * **A. Immunosuppressive effect of placental hormones:** High local concentrations of **Progesterone** and **hCG** at the maternal-fetal interface suppress maternal T-cell activity and promote a shift from a pro-inflammatory (Th1) to an anti-inflammatory (**Th2**) cytokine profile. * **B. Absence of HLA molecules in villous trophoblast:** The syncytiotrophoblast (which is in direct contact with maternal blood) does not express classical **HLA Class I (A, B)** or **Class II** molecules. This prevents recognition and destruction by maternal cytotoxic T-cells. Instead, they express **HLA-G**, which inhibits Natural Killer (NK) cell activity. * **C. Production of blocking antibodies:** Maternal B-cells produce non-complement-fixing antibodies (asymmetric IgG) that bind to fetal antigens, "masking" them from maternal immune recognition without causing damage. ### **Clinical Pearls for NEET-PG:** * **The Th2 Shift:** Pregnancy is a Th2-dominant state. This explains why Th1-mediated autoimmune diseases (like Rheumatoid Arthritis) often improve during pregnancy, while Th2-mediated ones (like SLE) may flare. * **HLA-G:** This is a non-classical Class I MHC molecule unique to the extravillous trophoblast. It is the "shield" that protects the fetus from NK cell-mediated lysis. * **Indoleamine 2,3-dioxygenase (IDO):** An enzyme produced by the placenta that depletes tryptophan, effectively "starving" and inactivating maternal T-cells. * **Fas-L Expression:** Trophoblasts express Fas-ligand, which induces apoptosis in any maternal activated T-cells that attempt to attack the placenta.

Q: Which of the following is true regarding early deceleration in a cardiotocography (CTG)?

It is due to increased vagal tone in the fetus.. ### Explanation **1. Why Option A is Correct:** Early decelerations are characterized by a gradual decrease and return of the fetal heart rate (FHR) that coincides with the peak of a uterine contraction (the "mirror image" pattern). The underlying mechanism is **fetal head compression**. When the fetal head is compressed during a contraction, it leads to an increase in intracranial pressure, which stimulates the **vagus nerve**. This increased vagal tone results in a transient slowing of the heart rate. Because it is a physiological reflex rather than a sign of distress, early decelerations are considered benign. **2. Why the Other Options are Incorrect:** * **Option B (Fetal Hypoxia):** This is associated with **Late Decelerations**. Late decelerations occur due to uteroplacental insufficiency, where reduced blood flow during contractions leads to fetal hypoxia and metabolic acidosis. * **Option C (Raised Maternal BP):** Maternal hypertension (e.g., Preeclampsia) is a risk factor for uteroplacental insufficiency, which would more likely cause *late* decelerations, not early ones. * **Option D (Cord Compression):** This is the hallmark cause of **Variable Decelerations**. These are abrupt in onset and vary in shape and timing relative to contractions. **3. High-Yield Clinical Pearls for NEET-PG:** * **Early Deceleration:** "Mirror image" of contraction; Nadir of FHR matches Peak of contraction; Cause: **Head compression** (Vagal). * **Late Deceleration:** Nadir of FHR occurs *after* the peak of contraction; Cause: **Uteroplacental insufficiency** (Hypoxia). * **Variable Deceleration:** Most common type; V-shaped; Cause: **Umbilical cord compression**. * **Sinusoidal Pattern:** Associated with severe **fetal anemia** (e.g., Rh isoimmunization) or fetal hemorrhage. * **Management:** Early decelerations require no active intervention; they are not indicative of fetal compromise.

Q: Which of the following is NOT a fetal heart tracing finding in maternal carbon monoxide poisoning?

Marked beat-to-beat variability. **Explanation:** Maternal carbon monoxide (CO) poisoning leads to fetal hypoxia through two primary mechanisms: the formation of **carboxyhemoglobin (COHb)**, which reduces the oxygen-carrying capacity of blood, and a **leftward shift of the oxyhemoglobin dissociation curve**, which prevents the release of oxygen to fetal tissues. **Why "Marked beat-to-beat variability" is the correct answer:** Fetal hypoxia typically leads to a **depression** of the fetal central nervous system (CNS). In cases of CO poisoning, the resulting hypoxia and acidosis cause a **decrease** in variability, not an increase. Marked (saltatory) variability is usually associated with acute umbilical cord compression or early hypoxia, but it is not a characteristic finding of the profound, systemic cellular hypoxia caused by CO poisoning. **Analysis of incorrect options:** * **Elevated baseline (Tachycardia):** This is an early compensatory response to fetal hypoxia as the fetus attempts to increase cardiac output to maintain tissue perfusion. * **Absence of accelerations:** Accelerations signify a healthy, reactive CNS. In CO poisoning, the hypoxic state leads to a non-reactive stress test (NST). * **Decreased beat-to-beat variability:** This is a hallmark finding of fetal acidemia and CNS depression resulting from prolonged or severe CO exposure. **Clinical Pearls for NEET-PG:** * **Affinity:** CO has an affinity for hemoglobin **200–250 times** greater than oxygen. * **Fetal Impact:** Fetal COHb levels are typically **10–15% higher** than maternal levels because fetal hemoglobin has an even higher affinity for CO, and clearance is slower. * **Treatment:** The definitive treatment is **100% normobaric oxygen** for the mother. Hyperbaric oxygen (HBO) is indicated if the mother is unconscious, has neurological symptoms, or has a COHb level >20%.

Q: Absent stomach bubble on antenatal ultrasonography is an important finding for the antenatal diagnosis of?

Esophageal atresia in the fetus. **Explanation:** The presence of a fluid-filled **stomach bubble** on antenatal ultrasonography is a marker of a functional upper gastrointestinal tract. Fetal swallowing of amniotic fluid begins around 10–12 weeks; this fluid then passes through the esophagus into the stomach. **1. Why Esophageal Atresia is correct:** In **Esophageal Atresia (EA)**, there is a physical discontinuity of the esophagus. If there is no distal tracheoesophageal fistula (TEF), or if the fistula is too narrow, the swallowed amniotic fluid cannot reach the stomach. This results in an **absent or persistently small stomach bubble**. This finding is often associated with **polyhydramnios**, as the fetus cannot effectively recirculate amniotic fluid. Note: In 90% of cases (Type C EA with distal TEF), a small stomach bubble may still be seen due to air/fluid entering from the trachea. **2. Why other options are incorrect:** * **Congenital heart disease:** Typically diagnosed via fetal echocardiography (e.g., four-chamber view abnormalities). It does not directly affect the presence of the stomach bubble. * **Omphalocele:** This is a ventral wall defect where bowel loops (and sometimes the liver) herniate into the umbilical cord. While the stomach may be displaced into the sac, it is usually visible. * **Spina bifida:** A neural tube defect diagnosed by visualizing spinal dysraphism or cranial signs (Lemon/Banana signs). It does not interfere with swallowing. **Clinical Pearls for NEET-PG:** * **Differential Diagnosis for Absent Stomach Bubble:** Esophageal atresia, diaphragmatic hernia (stomach moved into the chest), facial clefts/masses (inability to swallow), or neuromuscular disorders. * **VACTERL Association:** Always screen for Vertebral, Anal, Cardiac, TEF, Renal, and Limb anomalies when EA is suspected. * **Double Bubble Sign:** Distinct from "absent bubble," this indicates **Duodenal Atresia**.

Q: Which of these is the function of Decidua basalis of the endometrium?

Formation of placenta. **Explanation:** The **Decidua** is the modified functional layer of the endometrium during pregnancy, transformed under the influence of progesterone (decidualization). It is divided into three distinct regions based on its anatomical relationship to the implanted embryo: 1. **Decidua Basalis (Correct Answer):** This is the part of the decidua located directly deep to the conceptus (at the site of implantation). It interacts with the fetal chorion frondosum to form the **maternal component of the placenta**. It provides the vascular environment necessary for nutrient and gas exchange. 2. **Decidua Capsularis:** The portion that covers the blastocyst, separating it from the uterine cavity. 3. **Decidua Parietalis:** The remainder of the endometrium lining the rest of the uterine cavity. **Analysis of Incorrect Options:** * **Options A & D:** These describe the cyclical changes of the **functional layer** of the endometrium during a non-pregnant menstrual cycle (Proliferative phase under Estrogen and Secretory phase under Progesterone). Once pregnancy occurs, these changes transition into decidualization. * **Option C:** Shedding during the menstrual phase involves the *Stratum Functionale*. In pregnancy, the decidua is maintained to support the fetus and is only shed after parturition (childbirth). **High-Yield NEET-PG Pearls:** * **Nitabuch’s Layer:** A fibrinoid layer between the decidua basalis and the cytotrophoblast that prevents over-invasion of the placenta. Absence of this layer leads to **Placenta Accreta**. * **Arias-Stella Reaction:** Hypersecretory changes in endometrial glands (enlarged nuclei) seen in pregnancy; it can be mistaken for malignancy but is a normal response to HCG. * The **Chorion Frondosum** (fetal part) + **Decidua Basalis** (maternal part) = **The Placenta**.

Q: Presence of gas in the great vessels of a fetus indicates which of the following?

Fetal death. **Explanation:** The presence of gas in the fetal heart or great vessels (aorta and vena cava) is known as **Robert’s Sign**. This is a classic radiological sign of **intrauterine fetal death (IUFD)**. **Why it occurs:** When a fetus dies, the blood undergoes decomposition and fermentation. This process releases gases (primarily nitrogen, along with some oxygen and carbon dioxide) into the circulatory system. On an X-ray or ultrasound, this appears as linear or branching radiolucency within the fetal trunk. It is one of the earliest signs of fetal death, often appearing within 12 to 24 hours after cessation of the fetal heartbeat. **Analysis of Incorrect Options:** * **A. Fetal distress:** This is a clinical state of hypoxia during labor or pregnancy, usually diagnosed via abnormal fetal heart rate patterns or biophysical profile. It does not involve gas formation. * **B & D. Postmature/Premature fetus:** These terms refer to the gestational age of the fetus (post-term vs. pre-term). Neither condition causes spontaneous gas formation in the vessels unless fetal death has occurred. **High-Yield Clinical Pearls for NEET-PG:** * **Robert’s Sign:** Gas in the fetal great vessels (earliest sign, ~12 hours). * **Spalding’s Sign:** Overlapping of fetal skull bones due to liquefaction of the brain and loss of alignment (appears after 4–7 days). * **Deuel’s Halo Sign:** Elevation of the fetal scalp fat due to edema, creating a "halo" appearance. * **Curvature of the Spine:** Excessive angulation or collapse of the fetal spine due to loss of muscle tone. * **Gold Standard:** Today, the definitive diagnosis of IUFD is made via **ultrasound** by demonstrating the absence of fetal cardiac activity.

Q: Which of the following conditions is NOT associated with twin pregnancy?

Oligohydramnios. In twin pregnancies, the physiological and mechanical demands on the mother and the fetuses are significantly increased, leading to specific complications. **Why Oligohydramnios is the Correct Answer:** Twin pregnancy is typically associated with **Polyhydramnios** (excess amniotic fluid), not oligohydramnios. This occurs due to increased fetal urine production from two fetuses and is especially common in Monochorionic Diamniotic (MCDA) twins as a component of Twin-to-Twin Transfusion Syndrome (TTTS), where the recipient twin develops polyhydramnios. While oligohydramnios can occur in the "stuck twin" (donor) in TTTS, it is a complication of the *syndrome*, whereas the pregnancy as a whole is classically associated with an increased total liquor volume. **Explanation of Incorrect Options:** * **Pre-eclampsia:** The risk is 2–3 times higher in multifetal gestations due to increased placental mass and higher levels of anti-angiogenic factors (sFlt-1). * **Antepartum Hemorrhage (APH):** There is an increased risk of both **Placenta Previa** (due to the larger surface area of the placenta(s) encroaching on the lower segment) and **Abruptio Placentae** (often following the sudden decompression after the birth of the first twin). * **Atonic Uterus:** Overdistension of the myometrium by multiple fetuses and polyhydramnios leads to poor uterine contractility after delivery, making **Postpartum Hemorrhage (PPH)** a major risk. **NEET-PG High-Yield Pearls:** * **Most common complication:** Anemia (Iron deficiency). * **Most common fetal complication:** Prematurity. * **TTTS:** Occurs only in Monochorionic twins; characterized by "Poly-Oli" sequence (Polyhydramnios in recipient, Oligohydramnios in donor). * **Weight gain:** Recommended weight gain for a normal BMI woman with twins is 17–25 kg.

Question 1

The fetus, which is foreign to the mother, is not rejected due to which of the following reasons?

Accepted Answer

All of the above

Answer

Immunosuppressive effect of placental hormones

Answer

Absence of HLA molecules in villous trophoblast

Answer

Production of blocking antibodies

Question 2

Which of the following is true regarding early deceleration in a cardiotocography (CTG)?

Accepted Answer

It is due to increased vagal tone in the fetus.

Answer

It is due to fetal hypoxia.

Answer

It is due to raised blood pressure in the mother.

Answer

It is due to cord compression.

Question 3

Which of the following is NOT a fetal heart tracing finding in maternal carbon monoxide poisoning?

Accepted Answer

Marked beat-to-beat variability

Answer

Elevated baseline

Answer

Absence of accelerations

Answer

Decreased beat-to-beat variability

Question 4

Absent stomach bubble on antenatal ultrasonography is an important finding for the antenatal diagnosis of?

Accepted Answer

Esophageal atresia in the fetus

Answer

Congenital heart disease in the fetus

Answer

Omphalocele in the fetus

Answer

Spina bifida in the fetus

Question 5

Which of these is the function of Decidua basalis of the endometrium?

Accepted Answer

Formation of placenta

Answer

Monthly proliferation in response to estrogen

Answer

Shedding during menstrual phase

Answer

Secretory changes in response to progesterone

Question 6

Which of the following statements is true regarding Acute Fatty Liver of Pregnancy?

Accepted Answer

Occurs due to LCHAD deficiency (long-chain 3-hydroxyacyl coenzyme A dehydrogenase)

Answer

Characterized by macrovesicular steatosis with periportal sparing

Answer

Associated with an increase in fibrinogen, ammonia, and SGOT

Answer

Most cases are asymptomatic

Question 7

Presence of gas in the great vessels of a fetus indicates which of the following?

Accepted Answer

Fetal death

Answer

Fetal distress

Answer

Postmature fetus

Answer

Premature fetus

Question 8

Which of the following conditions is NOT associated with twin pregnancy?

Accepted Answer

Oligohydramnios

Answer

Pre-eclampsia

Answer

Antepartum hemorrhage

Answer

Atonic uterus

Question 9

A 32-week pregnant woman, who was HBsAg positive during her first pregnancy 8 years ago, presents with normal LFT, HBsAg positive, HBeAg negative, and HBV DNA of 90,000 copies/ml. Her first child received hepatitis B immunoglobulin and vaccination shortly after birth and is currently HBsAg negative. Which of the following statements is true regarding this current scenario?

Accepted Answer

The patient can be monitored without antivirals, and the baby should receive immunoglobulin and active immunization soon after delivery.

Answer

There is a very high risk of hepatitis B transmission to the baby.

Answer

Entecavir is safe in pregnancy and should be started as early as possible for the mother.

Answer

Antiviral therapy against hepatitis B is contraindicated in pregnancy.

Question 10

A 30 weeks pregnant multigravida presents with hypertension, proteinuria, and pedal edema. Which antihypertensive medication is appropriate for managing the blood pressure in this patient?

Accepted Answer

Labetalol

Answer

Guanethidine

Answer

Atenolol

Answer

Captopril

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

On this page

Practice by Chapter

Want unlimited practice?