Maternal-Fetal Medicine Practice Questions

Q: In a patient with a prosthetic heart valve, at which gestational age is it generally recommended to switch from warfarin to heparin?

36 weeks. **Explanation:** The management of anticoagulation in pregnant women with prosthetic heart valves is a critical balance between preventing maternal valve thrombosis and minimizing fetal/neonatal risks. **Why 36 weeks is correct:** Warfarin is a highly effective anticoagulant but crosses the placenta. The primary concern near term is the risk of **fetal intracranial hemorrhage** during the mechanical stress of labor and delivery if the fetus is anticoagulated. Therefore, it is standard practice to switch from Warfarin to **Unfractionated Heparin (UFH) or Low Molecular Weight Heparin (LMWH)** at **36 weeks** of gestation. Heparin does not cross the placenta, ensuring the fetus is not anticoagulated during birth. Additionally, UFH has a short half-life and can be easily reversed with Protamine Sulfate if urgent delivery is required. **Analysis of Incorrect Options:** * **A & B (28 and 32 weeks):** Switching this early unnecessarily increases the risk of maternal valve thrombosis. Warfarin is generally superior to heparin for preventing valve thrombosis; thus, it is continued as long as safely possible. * **D (Postpartum):** Waiting until postpartum is dangerous. If the patient goes into labor while on Warfarin, the risk of neonatal hemorrhage is extremely high. Warfarin is typically restarted 6–12 hours after an uncomplicated delivery. **Clinical Pearls for NEET-PG:** * **Warfarin Embryopathy:** Occurs if Warfarin is used between **6–12 weeks** (stippled epiphyses, nasal hypoplasia). * **Preferred Regimen:** Many guidelines suggest Warfarin throughout pregnancy (if dose <5mg) due to lower valve failure rates, but **switching at 36 weeks is mandatory** regardless of the dose. * **Labor Management:** Heparin should be discontinued 4–6 hours (UFH) or 24 hours (LMWH) before planned induction or regional anesthesia.

Q: Placenta previa is characterized by all of the following except?

Presents in first trimester. **Explanation:** Placenta previa is a condition where the placenta is implanted in the lower uterine segment, partially or completely covering the internal os. It is a classic cause of **Antepartum Hemorrhage (APH)**. **Why Option C is the correct answer:** Placenta previa typically presents in the **late second or third trimester** (usually after 28 weeks of gestation). This is because the lower uterine segment begins to form and stretch during this period, causing the placental attachments to shear and bleed. Bleeding in the first trimester is categorized as an abortion, ectopic pregnancy, or molar pregnancy, not placenta previa. **Analysis of other options:** * **Painless bleeding (Option A):** This is the hallmark of placenta previa. Unlike placental abruption, the bleeding occurs without uterine contractions or pain. * **Causeless bleeding (Option B):** The bleeding usually occurs spontaneously without any preceding trauma or obvious inciting factor. * **Recurrent bleeding (Option D):** Bleeding episodes often recur as the lower segment continues to stretch and the cervix begins to efface as term approaches. The first episode (warning hemorrhage) is usually mild. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Transvaginal Ultrasound (TVS) is the gold standard for localization. * **Contraindication:** **Digital vaginal examination** is strictly contraindicated unless the patient is in the operating theater (Double Setup Examination), as it can provoke torrential hemorrhage. * **Stallworthy’s Sign:** A clinical finding where the fetal heart rate slows when the head is pushed into the pelvis, suggesting a posterior placenta previa. * **Risk Factors:** Multiparity, advanced maternal age, and previous Cesarean section (increases risk of Placenta Accreta Spectrum).

Q: Hemoconcentration is seen in which of the following conditions?

Preeclampsia. **Explanation:** In **Preeclampsia**, the fundamental pathophysiology involves widespread endothelial dysfunction. This leads to increased vascular permeability, causing fluid to leak from the intravascular compartment into the interstitial space (resulting in edema). Consequently, there is a **contraction of plasma volume**. While both plasma and red cell mass are affected, the reduction in plasma volume is disproportionately greater, leading to **hemoconcentration** (manifesting as an elevated hematocrit). This is a hallmark of the disease and distinguishes it from the physiological changes of a healthy pregnancy. **Analysis of Incorrect Options:** * **Normal Pregnancy:** This is characterized by **hemodilution**. While both plasma volume and red cell mass increase, the plasma volume increases by ~40–50% while red cell mass increases by only ~20–30%. This disproportion leads to "Physiological Anemia of Pregnancy." * **Ectopic Pregnancy:** If ruptured, this leads to hemorrhage and hypovolemia. Initially, the hematocrit may remain normal, but as compensatory mechanisms shift fluid into the vessels, it results in hemodilution (decreased hematocrit), not hemoconcentration. **High-Yield Clinical Pearls for NEET-PG:** * **Hematocrit Trend:** A rising hematocrit in a hypertensive pregnant woman is an ominous sign indicating worsening disease severity and significant plasma volume depletion. * **The "Gold Standard" Pathophysiology:** Preeclampsia is a disease of "theories," but **endothelial dysfunction** and **vasospasm** are the core mechanisms. * **Fluid Management:** Because patients with preeclampsia are hemoconcentrated but have leaky capillaries, they are at high risk for both pulmonary edema (if over-hydrated) and acute kidney injury (due to low intravascular volume).

Q: Which of the following is NOT a cause of polyhydramnios?

Occult spina bifida. **Explanation:** Polyhydramnios is defined as an Amniotic Fluid Index (AFI) >25 cm or a Single Deepest Pocket (SDP) >8 cm. It occurs due to either overproduction of fetal urine or impaired fetal swallowing. **Why "Occult Spina Bifida" is the correct answer:** In **Open Neural Tube Defects (ONTDs)**, such as *Anencephaly* or *Spina Bifida Cystica*, polyhydramnios occurs because of the transudation of fluid from the exposed meninges and the absence of the swallowing reflex (in anencephaly). However, **Occult Spina Bifida** (Spina Bifida Occulta) is a closed defect where the spinal cord and meninges are covered by skin. Since there is no exposed neural tissue or leakage of cerebrospinal fluid into the amniotic cavity, it does **not** cause polyhydramnios. **Analysis of incorrect options:** * **Diabetes Mellitus:** Maternal hyperglycemia leads to fetal hyperglycemia, causing **osmotic diuresis** and fetal polyuria. * **Swallowing Defects:** Conditions like esophageal atresia, duodenal atresia, or facial clefts prevent the fetus from recycling amniotic fluid, leading to accumulation. * **Multiple Pregnancy:** Specifically in Twin-to-Twin Transfusion Syndrome (TTTS), the recipient twin develops polyuria due to hypervolemia, resulting in polyhydramnios. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of polyhydramnios:** Idiopathic (approx. 50-60%). * **Most common fetal anomaly associated:** Anencephaly. * **Maternal Complications:** Abruptio placentae (due to sudden decompression), Postpartum Hemorrhage (PPH) due to uterine atony, and Cord Prolapse. * **Management:** Therapeutic amniocentesis or Indomethacin (reduces fetal urine output; contraindicated after 32 weeks due to risk of premature closure of Ductus Arteriosus).

Q: What is the investigation of choice in a diabetic mother with a doubtful abnormal fetus?

Sonography. **Explanation:** In a diabetic mother, the primary concern regarding a "doubtful abnormal fetus" is the presence of **congenital malformations**. Diabetes is a known teratogen, increasing the risk of structural defects (most commonly cardiac and neural tube defects). **1. Why Sonography is the Correct Choice:** Sonography (Targeted Imaging for Fetal Anomalies - TIFFA/Level II scan) is the **investigation of choice** because it allows for the direct, non-invasive visualization of fetal anatomy. It is the gold standard for detecting structural anomalies such as sacral agenesis (caudal regression syndrome), ventricular septal defects, and anencephaly, which are more prevalent in diabetic pregnancies. **2. Analysis of Incorrect Options:** * **Glycosylated Hemoglobin (HbA1c):** While high HbA1c levels in the first trimester correlate with an increased risk of malformations, it is a **predictive marker**, not a diagnostic tool for identifying an existing fetal abnormality. * **Amniocentesis & Chorionic Villi Biopsy (CVS):** These are invasive procedures used primarily for **genetic and chromosomal analysis** (karyotyping). Since maternal diabetes typically causes structural/morphological defects rather than chromosomal aneuploidies, these are not the first-line investigations for a "doubtful abnormal fetus" unless a genetic syndrome is specifically suspected. **Clinical Pearls for NEET-PG:** * **Most common anomaly** in infants of diabetic mothers: **Cardiac defects** (specifically VSD). * **Most specific anomaly** for diabetes: **Caudal Regression Syndrome** (Sacral agenesis). * **Best time for anomaly scan:** 18–20 weeks of gestation. * Poor glycemic control (HbA1c >8.5%) significantly increases the risk of congenital malformations.

Q: A patient presents with signs of an abortus in the uterus and a dilated, open cervical os. This clinical presentation is suggestive of which of the following conditions?

Inevitable abortion. ### Explanation The clinical presentation of products of conception (abortus) still within the uterus accompanied by a **dilated/open cervical os** is the hallmark of an **Inevitable Abortion**. In this stage, the process of miscarriage has progressed to a point where it cannot be stopped or reversed. #### Analysis of Options: * **Inevitable Abortion (Correct):** Defined by vaginal bleeding, uterine cramps, and an **open internal os**. The products of conception are still inside the uterus but are destined to be expelled. * **Missed Abortion:** Characterized by fetal demise where the products of conception are retained in the uterus for a prolonged period. Crucially, the **cervical os remains closed**, and there is often a disappearance of pregnancy symptoms. * **Threatened Abortion:** Presents with vaginal bleeding, but the **cervical os is closed**, and the fetus is alive (cardiac activity present). It is the only stage of spontaneous abortion that is potentially reversible. * **Complete Abortion:** Occurs when all products of conception have been expelled. On examination, the **cervical os has usually closed**, and the uterus is contracted and empty on ultrasound. #### NEET-PG High-Yield Pearls: 1. **Cervical Os Status:** This is the most critical physical finding to differentiate types of abortion. If the os is **open**, it is either Inevitable or Incomplete. If the os is **closed**, it is either Threatened, Missed, or Complete. 2. **Management:** For Inevitable abortion, the management is typically **suction evacuation** (if <12 weeks) or medical induction to prevent infection and heavy hemorrhage. 3. **Incomplete Abortion:** Similar to inevitable (open os), but some products have already been expelled, often described as "fleshy masses" per vaginum.

Q: True regarding rubella infection in pregnancy is:

IgM antibodies in fetus reflects immunity. **Explanation:** **Why Option C is Correct:** The detection of **IgM antibodies** in the fetus or neonate is diagnostic of a congenital infection. Unlike IgG, maternal IgM antibodies are large molecules that **cannot cross the placenta**. Therefore, if IgM is present in the fetal blood (usually detected via cordocentesis after 22 weeks) or in the newborn, it indicates that the fetus has mounted its own immune response to an active infection. In the context of this question, it "reflects immunity" in the sense of an endogenous fetal immune response to the virus. **Analysis of Incorrect Options:** * **Option A:** The risk of **congenital transmission** is actually highest in the **first trimester** (up to 80-90%) and again very late in the third trimester. However, the risk of **congenital malformations** (Congenital Rubella Syndrome) is highest if the infection occurs before 12 weeks and is virtually zero after 20 weeks. * **Option B:** The Rubella vaccine (MMR) is a **Live Attenuated Vaccine**. It is strictly **contraindicated during pregnancy** due to the theoretical risk of infecting the fetus. Women should be advised to avoid pregnancy for at least 1 month (28 days) after vaccination. * **Option D:** Rubella is caused by the Rubivirus, which is a **positive-sense, single-stranded RNA virus** (Togaviridae family), not a DNA virus. **High-Yield Clinical Pearls for NEET-PG:** * **Gregg’s Triad:** The classic presentation of Congenital Rubella Syndrome (CRS) includes **Cataracts, Sensorineural hearing loss (most common), and Cardiac defects** (PDA is most common; Peripheral Pulmonary Artery Stenosis is most specific). * **Blueberry Muffin Rash:** Seen in neonates due to extramedullary hematopoiesis. * **Diagnosis:** If a pregnant woman is exposed, the first step is to check her **IgG status**. If she is IgG positive, she is immune and the fetus is safe.

Question 1

In a patient with a prosthetic heart valve, at which gestational age is it generally recommended to switch from warfarin to heparin?

Accepted Answer

36 weeks

Answer

28 weeks

Answer

32 weeks

Answer

Postpartum

Question 2

Placenta previa is characterized by all of the following except?

Accepted Answer

Presents in first trimester

Answer

Painless bleeding

Answer

Causeless bleeding

Answer

Recurrent bleeding

Question 3

Hemoconcentration is seen in which of the following conditions?

Accepted Answer

Preeclampsia

Answer

Normal pregnancy

Answer

Ectopic pregnancy

Answer

All of the above

Question 4

Which of the following is NOT a cause of polyhydramnios?

Accepted Answer

Occult spina bifida

Answer

Diabetes mellitus

Answer

Swallowing defects in fetus

Answer

Multiple pregnancy

Question 5

A G4, P1, L0 female presents for antenatal checkup at 12 weeks of gestation. She has had two prior 1st trimester surgical MTPs and delivered a 7-month-old boy in her last pregnancy who died 14 days after birth due to jaundice. Her blood group is B negative, and she was monitored with repeated blood tests during her last pregnancy. There is no history of anti-D administration. What is true regarding her management?

Accepted Answer

Monitor the pregnancy with Middle Cerebral Artery (MCA) Peak Systolic Velocity (PSV) values

Answer

Perform weekly Indirect Coombs Test (ICT) for anti-D titres

Answer

Administer anti-D injection at 28 weeks if ICT is negative

Answer

Administer anti-D injection irrespective of the ICT result

Question 6

What is the investigation of choice in a diabetic mother with a doubtful abnormal fetus?

Accepted Answer

Sonography

Answer

Glycosylated hemoglobin

Answer

Amniocentesis

Answer

Chorionic villi biopsy

Question 7

What is the best management to prevent heart failure in a pregnant woman with severe mitral stenosis?

Accepted Answer

Balloon mitral valvotomy during the second trimester

Answer

Continuous furosemide therapy throughout pregnancy

Answer

Digoxin for all patients with heart failure

Answer

Admission at 30 weeks gestation

Question 8

A patient presents with signs of an abortus in the uterus and a dilated, open cervical os. This clinical presentation is suggestive of which of the following conditions?

Accepted Answer

Inevitable abortion

Answer

Missed abortion

Answer

Threatened abortion

Answer

Complete abortion

Question 9

A patient at 17 weeks gestation is diagnosed with intrauterine fetal demise. She returns to your office 5 weeks later and has not had a miscarriage, although she has had some occasional spotting. This patient is at increased risk for what complication?

Accepted Answer

Consumptive coagulopathy with hypofibrinogenemia

Answer

Septic abortion

Answer

Recurrent abortion

Answer

Future infertility

Question 10

True regarding rubella infection in pregnancy is:

Accepted Answer

IgM antibodies in fetus reflects immunity

Answer

Risk of congenital infection is more in last trimester

Answer

Vaccination is indicated in pregnancy for protection

Answer

It is caused by DNA virus

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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