Maternal-Fetal Medicine Practice Questions

Q: A multiparous woman at 38 weeks of gestation, with a history of previous lower segment cesarean section (LSCS), presents in shock. What is the most likely differential diagnosis?

All of the above. **Explanation:** The clinical presentation of a multiparous woman in late pregnancy with a history of a previous uterine scar (LSCS) presenting in shock constitutes an obstetric emergency. The correct answer is **"All of the above"** because each of these conditions can lead to massive hemorrhage and hypovolemic shock. 1. **Uterine Rupture:** This is the most critical suspicion in a patient with a previous LSCS. The scarred uterus is a weak point; rupture can lead to massive intraperitoneal hemorrhage, fetal distress, and rapid maternal collapse (shock). 2. **Abruptio Placentae:** Multiparous women are at higher risk for placental abruption. Severe "concealed" or "revealed" hemorrhage can lead to shock, often out of proportion to visible blood loss, and may trigger DIC. 3. **Placenta Previa:** A previous LSCS is a major risk factor for placenta previa and the morbidly adherent placenta spectrum (Placenta Accreta). Sudden, painless, profuse bleeding can lead to immediate hemorrhagic shock. **Why "All of the above" is correct:** In a NEET-PG context, when a patient presents in shock during the third trimester, you must consider all causes of **Antepartum Hemorrhage (APH)** and **Uterine Rupture**. While the previous scar points strongly toward rupture, it also significantly increases the risk of abnormal placentation (Previa/Accreta). **Clinical Pearls for NEET-PG:** * **Scar Tenderness:** The earliest sign of impending uterine rupture in a patient with a previous LSCS. * **Couvelaire Uterus:** Associated with severe Abruptio Placentae (extravasation of blood into the myometrium). * **Classic Triad of Rupture:** Sudden abdominal pain, cessation of uterine contractions, and recession of the presenting part (Station becomes higher). * **Management:** Immediate resuscitation (ABC), large-bore IV lines, and emergency laparotomy/delivery.

Q: What is the most sensitive test for acute fetal distress?

Loss of beat-to-beat variation of heart rate. **Explanation:** **1. Why Option B is Correct:** Beat-to-beat variability (short-term variability) is the most sensitive indicator of fetal well-being. It reflects the continuous interaction between the fetal sympathetic and parasympathetic nervous systems. In the presence of **acute fetal distress (hypoxia/acidosis)**, the fetal brain and autonomic nervous system are the first to be affected, leading to a "flat" or diminished baseline variability. The **loss of beat-to-beat variation** is often the earliest sign of fetal compromise, preceding late decelerations. **2. Why Other Options are Incorrect:** * **Option A (Fresh meconium):** While meconium-stained liquor can be a sign of fetal distress, it is often a non-specific finding (seen in post-term pregnancies or breech presentation) and is less sensitive than heart rate changes. * **Option C (Increased fetal movements):** Fetal distress is typically associated with *decreased* or absent fetal movements (the "alarm signal"). While a sudden burst of hyperactive movement can occasionally precede fetal demise, it is not a standardized clinical test. * **Option D (Type 1 dips):** Also known as early decelerations, these are caused by fetal head compression during labor. They are considered physiological (benign) and are not indicative of fetal distress. **Clinical Pearls for NEET-PG:** * **Normal Variability:** 6 to 25 beats per minute. * **Most Specific Sign:** Late decelerations (Type II dips) are highly specific for uteroplacental insufficiency but may appear later than loss of variability. * **Gold Standard for Confirmation:** If CTG is non-reassuring, **Fetal Scalp Blood pH** is the most definitive test (pH < 7.20 indicates acidosis). * **Sinusoidal Pattern:** Indicates severe fetal anemia (e.g., Rh isoimmunization).

Q: What is the pathognomonic feature of abdominal pregnancy?

Fetus appears lateral to the lumbar spine on X-ray. **Explanation:** Abdominal pregnancy is a rare but serious form of ectopic pregnancy where the fetus develops within the peritoneal cavity. **Why Option A is correct:** The pathognomonic radiological sign of an abdominal pregnancy is the **fetus appearing lateral to or overlapping the maternal lumbar spine** on a lateral X-ray (the **"Spalding’s Sign"** is different; this is specifically about fetal position relative to the spine). In a normal intrauterine pregnancy, the thick muscular wall of the uterus keeps the fetus centered and anterior to the spine. In an abdominal pregnancy, the lack of a uterine wall allows the fetus to fall posteriorly or laterally, often overlapping the maternal vertebrae on a lateral view. **Analysis of Incorrect Options:** * **B. Small uterus:** While the uterus is indeed smaller than the period of gestation (as it is empty), this is a common finding in all ectopic pregnancies and is not pathognomonic. * **C. Fetus easily palpable:** While "fetal parts felt easily" is a classic clinical sign due to the absence of the uterine wall, it is subjective and can be confused with a very thin uterine wall or a ruptured uterus. * **D. Positive pregnancy test:** This only confirms pregnancy, not the location. **NEET-PG High-Yield Pearls:** * **Clinical Sign:** Failure of the uterus to contract after oxytocin administration (since the fetus is extrauterine). * **Diagnosis:** Ultrasound is the primary modality, but **MRI** is the gold standard for assessing placental attachment to abdominal organs. * **Management:** The placenta is usually left in situ (if attached to vital organs) to avoid massive hemorrhage; methotrexate may be used postoperatively to accelerate its involution.

Q: Non-immune hydrops fetalis is seen in which of the following conditions?

Alpha thalassemia major. **Explanation:** **Hydrops Fetalis** is defined as the abnormal accumulation of fluid in two or more fetal compartments (e.g., ascites, pleural effusion, pericardial effusion, or skin edema). It is categorized into **Immune** (due to maternal antibodies) and **Non-Immune (NIHF)**, which now accounts for ~90% of cases. **Why Alpha Thalassemia Major is correct:** Alpha thalassemia major (Hb Bart’s; genotype --/--) is the most common cause of NIHF in Southeast Asian populations. In this condition, the absence of alpha-globin chains leads to the formation of gamma-tetramers (Hb Bart’s). These have an extremely high affinity for oxygen, failing to release it to fetal tissues. This causes **severe tissue hypoxia**, high-output cardiac failure, and subsequent hydrops. **Analysis of Incorrect Options:** * **B. Rh Incompatibility:** This is the classic cause of **Immune Hydrops Fetalis**. It occurs when a sensitized Rh-negative mother carries an Rh-positive fetus, leading to erythroblastosis fetalis. * **C. Bilateral Renal Agenesis:** This condition leads to **Oligohydramnios** (Potter sequence) due to lack of fetal urine production. It does not typically cause fluid accumulation or hydrops. * **D. Maternal Rubella:** While TORCH infections (like CMV, Syphilis, and Parvovirus B19) are major causes of NIHF, Rubella is more commonly associated with **Congenital Rubella Syndrome** (cataracts, PDA, deafness) rather than hydrops. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of NIHF worldwide:** Cardiovascular anomalies. * **Most common infectious cause of NIHF:** Parvovirus B19 (targets erythrocyte precursors leading to aplastic anemia). * **Chromosomal association:** Turner Syndrome (45, XO) is the most common chromosomal cause of NIHF (often presenting with cystic hygroma). * **Diagnosis:** Ultrasound is the gold standard; look for "Mirror Syndrome" (maternal edema mimicking fetal hydrops).

Q: What is the most common type of monozygotic twin pregnancy based on the timing of cell division between the 4th and 8th day?

Monochorionic diamniotic twins. **Explanation:** The classification of monozygotic (identical) twins depends entirely on the **timing of the division** of the fertilized ovum. 1. **Monochorionic Diamniotic (MCDA) Twins (Correct Answer):** This occurs when division happens between **days 4 and 8** post-fertilization (at the blastocyst stage). By this time, the outer layer (trophoblast) has already differentiated, but the inner cell mass has not. This results in twins sharing one placenta (monochorionic) but having separate amniotic sacs (diamniotic). This is the **most common type of monozygotic pregnancy**, accounting for approximately 70–75% of cases. 2. **Dichorionic Diamniotic (DCDA) Twins (Option D):** Division occurs early, between **days 1 and 3** (at the morula stage). Since division happens before any differentiation, each twin develops its own placenta and amniotic sac. 3. **Monochorionic Monoamniotic (MCMA) Twins (Option B):** Division occurs late, between **days 8 and 13**. By this stage, the amniotic sac has already formed, so the twins share both the placenta and the sac. 4. **Conjoined (Siamese) Twins (Option A):** Division occurs very late, **after day 13** (at the embryonic disc stage), resulting in incomplete separation. **High-Yield NEET-PG Pearls:** * **Rule of 4s:** Remember the timeline in multiples of 4: 0–4 days (DCDA), 4–8 days (MCDA), 8–12 days (MCMA), >13 days (Conjoined). * **T-sign vs. Lambda sign:** On ultrasound, MCDA twins show a **"T-sign"** (thin membrane), while DCDA twins show a **"Lambda (λ) or Twin-peak sign"** (thick membrane). * **Risk:** MCDA twins are at unique risk for **Twin-to-Twin Transfusion Syndrome (TTTS)** due to vascular anastomoses in the shared placenta.

Q: Which of the following investigations is BEST used for placental localization?

Ultrasonography. **Explanation:** **Ultrasonography (USG)** is the gold standard and the investigation of choice for placental localization. It is preferred because it is non-invasive, cost-effective, lacks ionizing radiation, and provides high accuracy (nearly 95-98%). Transvaginal Sonography (TVS) is considered superior to Transabdominal Sonography (TAS) for diagnosing placenta previa, as it allows for better visualization of the internal os and the lower placental edge without the interference of maternal obesity or a full bladder. **Why other options are incorrect:** * **X-ray (Soft tissue placentography):** Historically used to identify the placental shadow, but it is now obsolete due to low sensitivity and the risks of fetal radiation exposure. * **Amniography:** This invasive procedure involves injecting radio-opaque dye into the amniotic sac. It is outdated and carries significant risks, such as infection, premature rupture of membranes, and fetal injury. * **Clinical Examination:** Digital vaginal examination (the "Double Setup" examination) is contraindicated in suspected placenta previa unless performed in an operating theater, as it can provoke life-threatening hemorrhage. **High-Yield NEET-PG Pearls:** * **Investigation of Choice:** Transvaginal Ultrasound (TVS) is safer and more accurate than TAS for placental localization. * **MRI:** Reserved for cases of suspected **Placenta Accreta Spectrum (PAS)** where USG is inconclusive. * **Placental Migration:** The phenomenon where the placenta appears to move away from the internal os as the lower uterine segment develops; hence, a definitive diagnosis of placenta previa is usually made after 28 weeks.

Q: A pregnant lady presented with painless bleeding in the 3rd trimester. What is the most common cause?

Placenta previa. ### Explanation **Correct Answer: A. Placenta previa** **Why it is correct:** In the third trimester, bleeding per vaginum is termed **Antepartum Hemorrhage (APH)**. The hallmark clinical presentation of **Placenta Previa** (where the placenta is implanted in the lower uterine segment) is **painless, causeless, and recurrent** bright red vaginal bleeding. Since the lower segment stretches and thins out in the third trimester, the inelastic placenta separates from its attachment, leading to open maternal sinuses and bleeding. Because there is no retroplacental clot formation or uterine tension, the patient does not experience pain. **Why the other options are incorrect:** * **B. Abruptio placentae:** This is the premature separation of a normally situated placenta. It typically presents with **painful** vaginal bleeding, uterine tenderness, and a "woody hard" uterus. It is the most common cause of *painful* APH. * **C. Vesicular mole:** While this causes vaginal bleeding, it typically presents in the **first or early second trimester** (usually before 20 weeks). It is characterized by "white currant" or grape-like vesicles and disproportionately high hCG levels. **NEET-PG High-Yield Pearls:** * **Investigation of Choice:** Transvaginal Ultrasound (TVS) is the gold standard for diagnosing the location of the placenta (safer and more accurate than transabdominal). * **The "Golden Rule":** Never perform a per-vaginal (PV) examination in a case of APH until Placenta Previa is ruled out by ultrasound, as it can provoke torrential, life-threatening hemorrhage (Stallworthy's sign). * **Most common cause of APH:** Abruptio placentae (overall), but for *painless* bleeding, it is always Placenta Previa.

Question 1

A multiparous woman at 38 weeks of gestation, with a history of previous lower segment cesarean section (LSCS), presents in shock. What is the most likely differential diagnosis?

Accepted Answer

All of the above

Answer

Placenta previa

Answer

Abruptio placenta

Answer

Uterine rupture

Question 2

What is the most sensitive test for acute fetal distress?

Accepted Answer

Loss of beat-to-beat variation of heart rate

Answer

Fresh meconium on induction of labor

Answer

Increased fetal movements

Answer

Type 1 dips in the second stage

Question 3

What is the pathognomonic feature of abdominal pregnancy?

Accepted Answer

Fetus appears lateral to the lumbar spine on X-ray

Answer

Small uterus

Answer

Fetus easily palpable

Answer

Positive pregnancy test

Question 4

Which of the following pregnancy complications is associated with polycythemia vera?

Accepted Answer

Stillbirth

Answer

Coagulopathy

Answer

Placental abruption

Answer

Placenta previa

Question 5

Non-immune hydrops fetalis is seen in which of the following conditions?

Accepted Answer

Alpha thalassemia major

Answer

Rh incompatibility

Answer

Bilateral renal agenesis

Answer

Maternal rubella

Question 6

What is the most common type of monozygotic twin pregnancy based on the timing of cell division between the 4th and 8th day?

Accepted Answer

Monochorionic diamniotic twins

Answer

Siamese presentation of monochorionic monoamniotic twins

Answer

Monochorionic monoamniotic twins

Answer

Dichorionic diamniotic twins

Question 7

What is the most common cause of placenta previa?

Accepted Answer

Previous cesarean section

Answer

Myomectomy

Answer

Primigravida

Answer

Multigravida

Question 8

Which of the following investigations is BEST used for placental localization?

Accepted Answer

Ultrasonography

Answer

X-ray

Answer

Amniography

Answer

Clinical examination

Question 9

A pregnant lady presented with painless bleeding in the 3rd trimester. What is the most common cause?

Accepted Answer

Placenta previa

Answer

Abruptio placentae

Answer

Vesicular mole

Answer

None of the above

Question 10

Surgery for mitral stenosis during pregnancy is ideally performed at which gestational age?

Accepted Answer

14 weeks

Answer

20 weeks

Answer

28 weeks

Answer

32 weeks

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

On this page

Practice by Chapter

Want unlimited practice?