Maternal-Fetal Medicine Practice Questions

Q: Which one of the following is categorized as a high-risk pregnancy?

Twins pregnancy. **Explanation:** A **high-risk pregnancy** is defined as one in which the mother, the fetus, or the newborn is at an increased risk of morbidity or mortality due to factors complicating the pregnancy. **Why "Twins Pregnancy" is Correct:** Multiple gestations (twins, triplets, etc.) are inherently high-risk because they significantly increase the risk of both maternal and fetal complications. * **Maternal risks:** Preeclampsia (3x higher risk), gestational diabetes, anemia, and postpartum hemorrhage (due to uterine overdistension). * **Fetal risks:** Preterm birth (the most common complication), intrauterine growth restriction (IUGR), malpresentation, and specific risks like Twin-to-Twin Transfusion Syndrome (TTTS) in monochorionic twins. **Analysis of Incorrect Options:** * **Birth order 3:** Generally, the "Grand Multipara" (Para 4 or more) is considered high-risk due to risks of placenta previa, malpresentation, and atonic PPH. A third pregnancy is typically considered a "safe" parity. * **Maternal height 150 cm:** In the Indian context, a "short-statured" mother is defined as having a height **<145 cm** (or 140 cm in some guidelines). 150 cm is above the threshold for increased risk of Cephalopelvic Disproportion (CPD). * **Blood group AB positive:** This is the "universal recipient" and does not pose an immunological risk. High-risk blood groups include **Rh-negative** (risk of isoimmunization) or rare blood groups where cross-matching may be difficult during emergencies. **NEET-PG High-Yield Pearls:** * **Primi-elderly:** Age >30 years (some texts say >35). * **Short Stature:** Height <145 cm (associated with contracted pelvis). * **Anemia in Pregnancy:** Hb <11 g/dL (WHO). * **Previous LSCS:** Always categorized as high-risk due to the risk of scar dehiscence or morbidly adherent placenta.

Q: A female presents with leaking and meconium-stained liquor at 32 weeks gestation. Which organism is she most likely infected with?

Listeria monocytogenes. **Explanation:** The presence of **meconium-stained liquor (MSL)** in a preterm pregnancy (especially before 34 weeks) is a classic clinical red flag for **Listeria monocytogenes** infection. **Why Listeria monocytogenes is correct:** Listeria is a gram-positive motile bacillus typically transmitted via contaminated food (unpasteurized cheese, cold meats). In pregnancy, it has a unique tropism for the placenta. It causes "granulomatosis infantiseptica" and is notorious for inducing **amnionitis**. A hallmark of Listeria infection is the passage of meconium in utero by a preterm fetus, which is otherwise rare, as the fetal gastrointestinal tract is usually too immature to pass meconium before 34 weeks unless severely stressed by this specific pathogen. **Why other options are incorrect:** * **CMV (Option A):** The most common congenital infection; typically presents with periventricular calcifications, microcephaly, and IUGR, but not acute MSL. * **Toxoplasma gondii (Option C):** Presents with the classic triad of hydrocephalus, chorioretinitis, and intracranial calcifications. It does not typically cause preterm leaking with MSL. * **HSV (Option D):** Usually transmitted during delivery through the birth canal, leading to skin-eye-mouth (SEM) lesions or encephalitis in the neonate. It is not associated with preterm meconium passage. **Clinical Pearls for NEET-PG:** * **Listeria** is the only Gram-positive bacteria that produces an **endotoxin**. * It shows **"tumbling motility"** at 25°C. * **Drug of Choice:** Ampicillin (Listeria is inherently resistant to cephalosporins). * **High-Yield Association:** Preterm labor + Fever + Meconium-stained liquor = Think **Listeria**.

Q: An Rh-negative woman married to a heterozygous Rh-positive man has three children. What is the probability that all three of their children are Rh-positive?

1:8. ### Explanation **1. Why the Correct Answer (C) is Right:** The inheritance of the Rh factor follows Mendelian genetics. In this scenario: * **Mother:** Rh-negative (Genotype: **dd**) * **Father:** Heterozygous Rh-positive (Genotype: **Dd**) Using a Punnett square for each pregnancy: * Possible offspring genotypes: **Dd** (Rh-positive) or **dd** (Rh-negative). * The probability of having an Rh-positive child in **each** pregnancy is **1/2 (50%)**. Since each pregnancy is an independent event, the probability of all three children being Rh-positive is calculated using the multiplication rule: **1/2 (1st child) × 1/2 (2nd child) × 1/2 (3rd child) = 1/8.** **2. Why Other Options are Wrong:** * **Option A (1:2):** This is the probability for a *single* child to be Rh-positive, not all three. * **Option B (1:4):** This would be the probability if only *two* children were Rh-positive. * **Option D (Zero):** This would only be possible if the father were also Rh-negative (dd). **3. Clinical Pearls for NEET-PG:** * **Rh Incompatibility:** Occurs only when the mother is Rh-negative and the fetus is Rh-positive. * **Homozygous Father:** If the father were homozygous Rh-positive (DD), **100%** of the children would be Rh-positive. * **Anti-D Prophylaxis:** Administered at 28 weeks of gestation and within 72 hours of delivery to prevent sensitization. * **Kleihauer-Betke Test:** Used to quantify fetal-maternal hemorrhage to determine the required dose of Rh-immunoglobulin. * **Critical Titer:** An Indirect Coombs Test (ICT) titer of **1:16** is generally considered the critical threshold requiring further fetal surveillance (e.g., MCA-PSV Doppler).

Q: A pregnant woman at 18 weeks gestation is found to have an abdominal pregnancy with the fetus and placenta attached to the omentum. What is the best course of action?

Removal of the fetus only. **Explanation:** In abdominal pregnancy, the management of the placenta is the most critical decision. Unlike an intrauterine pregnancy, there is no uterine contraction to constrict blood vessels after placental separation. **Why "Removal of the fetus only" is correct:** When the placenta is attached to a highly vascular or vital organ (like the omentum, bowel, or large vessels), attempting to remove it can lead to **uncontrollable, life-threatening hemorrhage**. The standard surgical recommendation is to ligate the umbilical cord close to the placenta and leave the placenta *in situ*. The placenta will eventually undergo spontaneous resorption, a process that can be monitored using serial β-hCG levels and ultrasound. **Analysis of Incorrect Options:** * **Option A:** Removing the placenta carries a high risk of massive bleeding because the site lacks the "living ligatures" (myometrial fibers) found in the uterus. * **Option B:** While the cord is ligated, the fetus must be removed to prevent infection, lithopedion formation, or maternal inflammatory response. Ligation alone is insufficient. * **Option C:** Waiting for viability is extremely dangerous. Abdominal pregnancies are associated with high maternal mortality (up to 7-8 times higher than tubal ectopic) and a high risk of sudden placental abruption or organ rupture. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Suggested by "painful fetal movements," easily palpable fetal parts, and an empty uterus on ultrasound. * **Placental Management:** If the placenta is left behind, **Methotrexate** is generally **avoided** as it causes rapid placental necrosis, leading to infection and abscess formation. * **Classification:** Primary abdominal pregnancy (rare) vs. Secondary (more common, usually following tubal abortion/rupture). * **Criteria:** Studdiford’s Criteria are used to diagnose primary abdominal pregnancy.

Q: Bleeding that follows partial or complete placental separation and dilation of the cervical os in the first 20 weeks is termed as what?

Incomplete abortion. ### Explanation **Correct Answer: C. Incomplete abortion** **1. Why it is correct:** An **incomplete abortion** is defined as the partial expulsion of the products of conception before 20 weeks of gestation. Pathophysiologically, it involves the separation of the placenta (either partially or completely) from the uterine wall. Because some products remain inside the uterus while others have passed, the **cervical os remains dilated** to allow for the passage of tissue. This leads to persistent bleeding and cramp-like pain. **2. Why the other options are incorrect:** * **A. Threatened abortion:** In this condition, the pregnancy is potentially viable. While bleeding occurs, the **cervical os remains closed**, and there is no expulsion of tissue. * **B. Complete abortion:** Here, all products of conception have been expelled. Consequently, the **cervical os closes**, the uterus is well-contracted (small for dates), and bleeding diminishes significantly. * **D. Preterm labor:** This refers to the onset of labor (regular contractions and cervical changes) **after 20 weeks** (or 28 weeks depending on regional definitions) but before 37 completed weeks. The question specifically mentions the first 20 weeks. **3. NEET-PG High-Yield Pearls:** * **Cervical Os Status:** This is the most critical clinical differentiator. The os is **closed** in Threatened and Complete abortions; it is **open** in Inevitable and Incomplete abortions. * **Ultrasonography (USG) findings:** In an incomplete abortion, USG shows "retained products of conception" (RPOCs) and an endometrial thickness usually >15 mm. * **Management:** The treatment of choice for incomplete abortion is **Dilation and Evacuation (D&E)** or medical management with Misoprostol to ensure the uterus is empty and to prevent hemorrhage or sepsis. * **Definition of Abortion:** Termination of pregnancy before **20 weeks** (WHO) or a fetal weight less than **500g**.

Q: Which fetal parameter is best for diagnosing Intrauterine Growth Restriction (IUGR)?

Abdominal circumference. **Explanation:** **Abdominal Circumference (AC)** is the most sensitive and reliable single parameter for diagnosing Intrauterine Growth Restriction (IUGR). This is because IUGR—specifically the asymmetrical type—primarily affects the fetal liver size and subcutaneous fat deposition. The fetal liver is the largest organ in the abdomen, and its size is directly dependent on glycogen storage. In cases of placental insufficiency, glycogen stores are depleted first, leading to a reduction in liver volume and a subsequent decrease in AC before other parameters are affected. **Analysis of Options:** * **Femur Length (FL):** Reflects skeletal growth. It is usually preserved until the late stages of growth restriction and is therefore not a sensitive early indicator. * **Head Circumference (HC):** In asymmetrical IUGR, the "brain-sparing effect" ensures that blood flow is prioritized to the brain. Consequently, HC remains relatively normal while the body wastes, making it a poor diagnostic tool for growth restriction. * **Crown-Rump Length (CRL):** This is the most accurate parameter for **gestational age estimation** in the first trimester, but it has no role in diagnosing IUGR, which is typically a second or third-trimester pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Best single parameter for IUGR:** Abdominal Circumference (AC). * **Best parameter for Gestational Age (1st Trimester):** Crown-Rump Length (CRL). * **Best parameter for Gestational Age (2nd/3rd Trimester):** Head Circumference (HC). * **Ponderal Index:** Used to differentiate between symmetrical and asymmetrical IUGR. * **Early sign of IUGR on Doppler:** Increased resistance/Reduced end-diastolic flow in the Umbilical Artery.

Q: What is the tocolytic of choice in HELLP syndrome?

Atosiban. **Explanation:** The management of HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) often necessitates delivery; however, if the pregnancy is extremely preterm and tocolysis is required to complete a course of corticosteroids for fetal lung maturity, **Atosiban** is the preferred choice. **Why Atosiban is correct:** Atosiban is an oxytocin receptor antagonist. Its primary advantage in HELLP syndrome is its **minimal side-effect profile**, particularly regarding the cardiovascular and hepatic systems. Unlike other tocolytics, it does not cause significant hypotension, tachycardia, or fluid overload, making it the safest option in a patient already physiologically compromised by endothelial dysfunction and potential coagulopathy. **Analysis of Incorrect Options:** * **Nifedipine (Calcium Channel Blocker):** While a first-line tocolytic in routine preterm labor, it can cause hypotension and may interfere with magnesium sulfate (increasing the risk of neuromuscular blockade). In HELLP, it may also mask or complicate the management of severe hypertension. * **Magnesium Sulfate:** While used in HELLP syndrome for **seizure prophylaxis** (neuroprotection), it is a very weak tocolytic and is not used primarily to arrest labor. * **Salbutamol (Beta-mimetics):** These are contraindicated in HELLP/Preeclampsia due to risks of maternal tachycardia, hyperglycemia, and, most critically, **pulmonary edema**, which is a known complication of severe preeclampsia. **NEET-PG High-Yield Pearls:** * **Drug of Choice for Tocolysis (General):** Nifedipine is generally the first-line tocolytic for preterm labor. * **Tocolytic in Heart Disease/Diabetes:** Atosiban is the preferred choice. * **HELLP Definitive Treatment:** Delivery of the fetus (usually after 34 weeks or if maternal/fetal condition deteriorates). * **Steroids in HELLP:** Dexamethasone is often used to increase platelet counts, though its effect on overall prognosis is debated.

Q: The Kleihauer Betke test for detecting fetal erythrocytes is based on which principle?

HbF is more resistant to acid elution than HbA.. ### Explanation The **Kleihauer-Betke (KB) test** is the gold standard for quantifying the volume of **fetal-maternal hemorrhage (FMH)**. **1. Why Option C is Correct:** The test relies on the biochemical difference between **Hemoglobin F (fetal)** and **Hemoglobin A (adult)**. When a maternal blood smear is exposed to an **acid bath (citrate-phosphate buffer)**, adult hemoglobin (HbA) is unstable and leaches out of the cells, leaving behind empty "ghost cells." In contrast, fetal hemoglobin (HbF) is **acid-resistant** and remains within the erythrocytes. When a counterstain (like eosin or erythrosin) is applied, the fetal cells take up the stain and appear bright pink/dark, while maternal cells appear pale or colorless. **2. Analysis of Incorrect Options:** * **Option A:** Cell size is not the distinguishing factor; both fetal and adult RBCs are similar in size (though fetal RBCs have a slightly higher MCV, it is not the basis for this chemical test). * **Option B:** While HbF does have a higher oxygen affinity than HbA, this physiological property is used for gas exchange in utero, not for laboratory elution tests. * **Option D:** The staining difference is a *result* of the acid elution process, not a primary difference in the innate staining affinity of the hemoglobins themselves. **3. Clinical Pearls for NEET-PG:** * **Indications:** Used to calculate the dose of **Rh Anti-D immunoglobulin** required after a large FMH (e.g., trauma, placental abruption). * **Formula:** Volume of FMH (mL) = (Number of fetal cells / Total cells counted) × Maternal Blood Volume (approx. 5000 mL). * **Dosage:** 300 µg of Anti-D neutralizes **30 mL** of fetal whole blood (or 15 mL of packed RBCs). * **Limitation:** The test is unreliable in mothers with conditions that elevate HbF, such as **Sickle Cell Anemia or Thalassemia**.

Question 1

Which one of the following is categorized as a high-risk pregnancy?

Accepted Answer

Twins pregnancy

Answer

Birth order 3

Answer

Maternal height 150 cm

Answer

Blood group AB positive

Question 2

A female presents with leaking and meconium-stained liquor at 32 weeks gestation. Which organism is she most likely infected with?

Accepted Answer

Listeria monocytogenes

Answer

Cytomegalovirus (CMV)

Answer

Toxoplasma gondii

Answer

Herpes simplex virus (HSV)

Question 3

An Rh-negative woman married to a heterozygous Rh-positive man has three children. What is the probability that all three of their children are Rh-positive?

Accepted Answer

1:8

Answer

1:2

Answer

1:4

Answer

Zero

Question 4

A pregnant woman at 18 weeks gestation is found to have an abdominal pregnancy with the fetus and placenta attached to the omentum. What is the best course of action?

Accepted Answer

Removal of the fetus only

Answer

Removal of both fetus and placenta

Answer

Laparoscopic ligation of umbilical cord

Answer

Close follow-up until viability and then delivery by laparotomy

Question 5

Bleeding that follows partial or complete placental separation and dilation of the cervical os in the first 20 weeks is termed as what?

Accepted Answer

Incomplete abortion

Answer

Threatened abortion

Answer

Complete abortion

Answer

Preterm labor

Question 6

Which fetal parameter is best for diagnosing Intrauterine Growth Restriction (IUGR)?

Accepted Answer

Abdominal circumference

Answer

Femur length

Answer

Head circumference

Answer

Crown-rump length (CRL)

Question 7

A woman presents with amenorrhea for 8 weeks, acute abdominal pain, and vaginal discharge. Which is the most appropriate investigation to rule out ectopic pregnancy?

Accepted Answer

Laparoscopy

Answer

Urine pregnancy test

Answer

Ultrasound (USG)

Answer

Hysteroscopy

Question 8

What is the tocolytic of choice in HELLP syndrome?

Accepted Answer

Atosiban

Answer

Nifedipine

Answer

Magnesium sulfate

Answer

Salbutamol

Question 9

Rh isoimmunization is typically identified in which trimester?

Accepted Answer

30-32 weeks

Answer

10-12 weeks

Answer

36 weeks

Answer

Immediately after delivery

Question 10

The Kleihauer Betke test for detecting fetal erythrocytes is based on which principle?

Accepted Answer

HbF is more resistant to acid elution than HbA.

Answer

Adult erythrocytes are larger than fetal erythrocytes.

Answer

HbA has higher oxygen affinity than HbF.

Answer

HbA takes up erythrosin stain less effectively than HbF.

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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