Maternal-Fetal Medicine Practice Questions

Q: A woman at 8 months of pregnancy complains of abdominal pain and slight vaginal bleeding. On examination, the uterine size is larger than expected for dates, and fetal heart sounds are absent. What is the most likely diagnosis?

Concealed hemorrhage. This question describes a classic presentation of **Abruptio Placentae**, specifically the **concealed variety**. ### **Explanation of the Correct Answer** In **concealed accidental hemorrhage**, blood collects behind the placenta (retroplacental clot) and does not escape through the cervix. This leads to several key clinical findings: * **Uterine size > Dates:** The accumulation of blood within the uterine cavity increases the fundal height beyond what is expected for the gestational age. * **Abdominal Pain:** The uterus becomes tense, tender, and "board-like" due to the irritating effect of the retroplacental hematoma. * **Absent Fetal Heart Sounds (FHS):** Severe placental separation leads to acute fetal hypoxia and intrauterine fetal death. * **Slight Bleeding:** Even in "concealed" cases, a small amount of dark vaginal bleeding (revealed component) is often present. ### **Why Other Options are Incorrect** * **A. Hydramnios:** While this causes a uterus larger than dates, it is usually painless and associated with easily audible (though muffled) FHS. It does not cause vaginal bleeding. * **C. Active Labor:** Labor presents with rhythmic contractions and cervical changes. It does not explain a uterus larger than dates or the sudden absence of FHS. * **D. Uterine Rupture:** This typically occurs during labor (often in a scarred uterus). On examination, fetal parts are easily palpable under the skin, and the uterus usually becomes **smaller** or recedes as the fetus is extruded into the peritoneal cavity. ### **NEET-PG High-Yield Pearls** * **Couvelaire Uterus:** A complication of concealed abruption where blood infiltrates the myometrium, giving it a port-wine appearance. * **Consumptive Coagulopathy (DIC):** More common in the concealed variety due to the release of thromboplastin into the maternal circulation. * **Classic Triad of Abruption:** Abdominal pain, uterine tenderness/hypertonicity, and vaginal bleeding.

Q: Which of the following is true about the amnion, except:

It has a rich blood supply.. The amnion is the innermost fetal membrane, characterized by its tough, thin, and transparent nature. Understanding its histology and function is high-yield for NEET-PG. ### **Explanation of the Correct Answer** **Option B (It has a rich blood supply)** is the correct answer because it is a **false statement**. The amnion is entirely **avascular**. It contains no blood vessels, lymphatics, or nerves. It derives its nutrition and oxygen primarily via diffusion from the amniotic fluid and the underlying vascularized decidua/chorion. ### **Analysis of Other Options** * **Option A (No lymph supply):** This is a true statement. As an avascular structure, it lacks a lymphatic drainage system. * **Option C (No nerve supply):** This is a true statement. The lack of nerve supply explains why procedures like amniocentesis do not cause pain when the needle pierces the amniotic sac (the pain felt is from the maternal abdominal wall and uterus). * **Option D (Dilates the cervix):** This is a true statement. During the first stage of labor, the intact "bag of waters" (amnion and chorion) acts as a hydrostatic wedge. According to **Pascal’s Law**, it transmits intrauterine pressure evenly to the cervix, aiding in effacement and dilatation. ### **High-Yield Clinical Pearls for NEET-PG** * **Structure:** The amnion consists of five layers, the innermost being a single layer of cuboidal/columnar epithelium. * **Tensile Strength:** The amnion provides the majority of the tensile strength of the fetal membranes, largely due to its **Type IV and V collagen** content. * **Amniotic Fluid Production:** Early in pregnancy, the amnion contributes to amniotic fluid production via active transport of solutes. * **Clinical Correlation:** Rupture of membranes (ROM) leads to the loss of the hydrostatic wedge, often resulting in a change in the mechanics of labor.

Q: Which of the following is true regarding vasa previa, except?

Mortality rate is 20% with undiagnosed cases. **Explanation:** **Vasa Previa** is a rare but life-threatening obstetric emergency where fetal vessels run through the fetal membranes, unprotected by placental tissue or the umbilical cord, across the internal os. **Why Option B is the correct answer (The "Except" statement):** The mortality rate for **undiagnosed** vasa previa is significantly higher than 20%, often cited between **50% and 95%**. Because the vessels are fetal in origin, rupture of membranes (spontaneous or artificial) leads to rapid fetal exsanguination. The 20% figure is inaccurate; conversely, when diagnosed prenatally, the survival rate increases to over 95%. **Analysis of other options:** * **Option A:** The incidence is approximately **1 in 2,500 to 1 in 5,000** pregnancies, though some studies suggest it may be as high as 1:1500 in high-risk populations (like IVF). It is considered a rare condition. * **Option C:** Risk factors include a **low-lying placenta**, placenta previa, velamentous cord insertion, succenturiate placental lobes, and pregnancies resulting from IVF. * **Option D:** Once diagnosed, a **planned Cesarean section** is mandatory (usually at 34–36 weeks) to avoid labor and the risk of membrane rupture, which would be fatal for the fetus. **NEET-PG High-Yield Pearls:** * **Classic Triad:** Rupture of membranes + Painless vaginal bleeding + Fetal bradycardia/distress. * **Diagnostic Test:** **Apt test** or **Ogita test** can differentiate fetal hemoglobin from maternal blood. * **Gold Standard Diagnosis:** Antenatal **Color Doppler Ultrasound** (showing pulsating vessels over the internal os). * **Management:** If diagnosed prenatally, admit by 30–32 weeks for monitoring and deliver via elective LSCS before labor begins.

Q: Which of the following antibodies is NOT typically involved in Rh isoimmunization?

Anti-Lewis. **Explanation:** Rh isoimmunization occurs when maternal antibodies cross the placenta and target fetal red blood cell antigens, leading to Hemolytic Disease of the Fetus and Newborn (HDFN). **Why Anti-Lewis is the correct answer:** The Lewis antigens (Le^a and Le^b) are not integral to the red cell membrane; they are plasma glycosphingolipids adsorbed onto the RBC surface. Most importantly, **Anti-Lewis antibodies are typically IgM.** Since IgM antibodies are large pentamers, they **cannot cross the placenta**. Furthermore, Lewis antigens are poorly expressed on fetal erythrocytes. Consequently, Anti-Lewis antibodies do not cause HDFN and are clinically insignificant in Rh isoimmunization. **Analysis of incorrect options:** * **Anti-D (Option D):** This is the most common and clinically significant antibody involved in Rh isoimmunization, occurring in Rh-negative mothers carrying Rh-positive fetuses. * **Anti-C and Anti-E (Options A & B):** These belong to the Rh blood group system (C, c, E, e). While less common than Anti-D, these are **IgG antibodies** that can cross the placenta and cause significant fetal hemolysis. **Clinical Pearls for NEET-PG:** * **"Lewis Lives" (mnemonic):** Lewis antibodies do not "kill" the fetus because they don't cross the placenta. * **Kell Antibodies:** "Kell Kills." Anti-Kell is the second most common cause of severe HDFN; it causes hemolysis AND suppresses fetal erythropoiesis. * **Antibody Titers:** For Anti-D, a critical titer (usually 1:16) indicates a high risk for fetal hydrops and necessitates further fetal surveillance (e.g., MCA-PSV doppler).

Q: What is pathognomonic of ectopic pregnancy?

Decidual casts. **Explanation:** **Why Decidual Casts are Correct:** A **decidual cast** is the pathognomonic finding of an ectopic pregnancy. It occurs when the endometrium, which has thickened and become "decidualized" due to rising progesterone levels from the pregnancy, is shed in its entirety as a single, fleshy, triangular piece of tissue. This happens because the ectopic pregnancy cannot sustain the hormonal levels required to maintain the uterine lining. While it mimics a miscarriage, the absence of chorionic villi on histopathological examination (Arias-Stella reaction may be present) confirms that the pregnancy is extrauterine. **Analysis of Incorrect Options:** * **A. Purple hemorrhagic pregnancy in the lower vagina:** This describes a **Choriocarcinoma** or a vaginal metastasis of a gestational trophoblastic neoplasm, not an ectopic pregnancy. * **C. Chadwick sign:** This is a bluish discoloration of the cervix, vagina, and labia caused by increased vascularity. It is a **presumptive sign of pregnancy** (both intrauterine and ectopic) but is not specific or pathognomonic for ectopic pregnancy. * **D. Postcoital hemorrhage:** This is a classic presentation of **Cervical Cancer** or cervical polyps/ectropion, unrelated to the location of a pregnancy. **High-Yield NEET-PG Pearls:** * **Classic Triad:** Amenorrhea, abdominal pain, and vaginal bleeding (present in only 50% of cases). * **Most common site:** Ampulla of the Fallopian tube. * **Arias-Stella Reaction:** Hypersecretory endometrium seen in ectopic pregnancy; it is suggestive but *not* pathognomonic (can occur in IUGR or molar pregnancy). * **Gold Standard Diagnosis:** Transvaginal Ultrasound (TVUS) + Serum β-hCG (Discriminatory zone: 1500–2000 mIU/mL).

Q: In a patient with a history of a previous stillbirth, what is the optimum time for delivery?

39 weeks. **Explanation:** The management of a pregnancy following a previous unexplained stillbirth requires a delicate balance between the risks of recurrent stillbirth and the risks associated with iatrogenic prematurity. **Why 39 weeks is correct:** Current clinical guidelines (including ACOG and RCOG) recommend delivery at **39 weeks 0 days to 39 weeks 6 days** for women with a history of a prior unexplained stillbirth, provided the current pregnancy is otherwise uncomplicated. Delivering at 39 weeks significantly reduces the risk of late-term stillbirth while ensuring the fetus has reached full maturity, thereby minimizing the risks of Respiratory Distress Syndrome (RDS) and NICU admissions associated with early-term delivery. **Analysis of Incorrect Options:** * **37 & 38 weeks (A & B):** Delivery before 39 weeks is considered "early-term." While it further reduces the risk of stillbirth, it is associated with higher rates of neonatal morbidity (respiratory issues, feeding difficulties, and jaundice). These are generally reserved for cases with co-existing complications like preeclampsia or FGR. * **40 weeks (D):** Waiting until the due date or beyond increases the risk of placental insufficiency and stillbirth, which is statistically higher in patients with a prior history of intrauterine fetal death (IUFD). **Clinical Pearls for NEET-PG:** * **Monitoring:** In patients with prior stillbirth, antenatal surveillance (NST/BPP) usually commences at **32–36 weeks**. * **The "Rule of 39":** For most elective inductions or repeat C-sections without maternal/fetal complications, 39 weeks is the "magic number" to ensure optimal neonatal outcomes. * **Recurrence Risk:** The risk of stillbirth in a subsequent pregnancy is approximately 2–5 times higher than in the general population.

Q: What is the most common cause of fetal ventriculomegaly?

Aqueductal stenosis. **Explanation:** **Ventriculomegaly** is defined as an atrial width of the lateral ventricles ≥10 mm. It is a common prenatal ultrasound finding that necessitates a thorough evaluation of the fetal neuroanatomy. **Why Aqueductal Stenosis is the Correct Answer:** **Aqueductal stenosis** is the most common cause of congenital obstructive (non-communicating) hydrocephalus, accounting for approximately **33–43% of cases**. It involves a narrowing or obstruction of the Aqueduct of Sylvius, which connects the third and fourth ventricles. This leads to a characteristic "upstream" dilation of the lateral and third ventricles, while the fourth ventricle remains normal in size. **Analysis of Incorrect Options:** * **Arnold-Chiari Malformation II:** This is a common cause of ventriculomegaly, but it is almost always associated with **neural tube defects** (specifically myelomeningocele). While high-yield, it is statistically less frequent as a primary cause compared to isolated aqueductal stenosis. * **Arnold-Chiari Malformation I:** This involves downward displacement of the cerebellar tonsils. It is rarely diagnosed prenatally and is generally not a common cause of fetal ventriculomegaly. * **Dandy-Walker Malformation:** This involves agenesis/hypoplasia of the cerebellar vermis and cystic dilation of the **fourth ventricle**. While it causes hydrocephalus, it is less common than aqueductal stenosis. **NEET-PG High-Yield Pearls:** * **Normal Atrial Width:** 15 mm is severe/frank hydrocephalus). * **The "Dangling Choroid" Sign:** A classic sonographic feature where the choroid plexus falls toward the dependent wall of the dilated lateral ventricle. * **X-linked Hydrocephalus:** The most common heritable form of aqueductal stenosis (HSAS), associated with the *L1CAM* gene mutation and characterized by "thumb adduction."

Question 1

A woman at 8 months of pregnancy complains of abdominal pain and slight vaginal bleeding. On examination, the uterine size is larger than expected for dates, and fetal heart sounds are absent. What is the most likely diagnosis?

Accepted Answer

Concealed hemorrhage

Answer

Hydramnios

Answer

Active labor

Answer

Uterine rupture

Question 2

Which of the following is true about the amnion, except:

Accepted Answer

It has a rich blood supply.

Answer

It has no lymph supply.

Answer

It has no nerve supply.

Answer

It dilates the cervix during labor.

Question 3

In a case of antepartum hemorrhage with BP = 80/60 mmHg, what is the treatment of choice?

Accepted Answer

Blood transfusion

Answer

Morphine

Answer

Placentography

Answer

Panhysterectomy

Question 4

Which of the following is true regarding vasa previa, except?

Accepted Answer

Mortality rate is 20% with undiagnosed cases

Answer

Incidence is 1:1500

Answer

Associated with low-lying placenta

Answer

Cesarean section is indicated

Question 5

Which of the following antibodies is NOT typically involved in Rh isoimmunization?

Accepted Answer

Anti-Lewis

Answer

Anti C

Answer

Anti E

Answer

Anti D

Question 6

What is pathognomonic of ectopic pregnancy?

Accepted Answer

Decidual casts

Answer

Purple hemorrhagic pregnancy in the lower vagina

Answer

Chadwick sign

Answer

Postcoital hemorrhage

Question 7

In a patient with a history of a previous stillbirth, what is the optimum time for delivery?

Accepted Answer

39 weeks

Answer

37 weeks

Answer

38 weeks

Answer

40 weeks

Question 8

A primigravida presents at 36 weeks of gestation with preterm premature rupture of membranes or leaking per vaginum. What is the appropriate management?

Accepted Answer

Lower Segment Caesarean Section (LSCS)

Answer

External Cephalic Version (ECV)

Answer

Induction of labor

Answer

Internal Podalic Version (IPV)

Question 9

What is the most common cause of fetal ventriculomegaly?

Accepted Answer

Aqueductal stenosis

Answer

Arnold Chiari malformation I

Answer

Arnold Chiari malformation II

Answer

Dandy-Walker malformation

Question 10

Which is the most sensitive screening test for congenital malformations in diabetic mothers?

Accepted Answer

Glycosylated hemoglobin (HbA1C)

Answer

Maternal serum alpha-fetoprotein (MS AFP)

Answer

Blood glucose

Answer

Amniotic fluid alpha-fetoprotein (AFP)

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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