Maternal-Fetal Medicine Practice Questions

Q: What is the lower end of the estimated risk of recurrence of anencephaly in subsequent pregnancies?

2%. ***2%*** - The estimated risk of recurrence for anencephaly in subsequent pregnancies ranges from 2% to 5%. - This 2% represents the **lower end** of the typical recurrence risk for anencephaly, a severe **neural tube defect (NTD)**. *1%* - A 1% recurrence risk is generally considered too low for a previous NTD such as anencephaly. - While it's lower than the recurrence risk for the general population (0.1%), it's still below the consensus range for a subsequent pregnancy. *4%* - A 4% recurrence risk falls within the accepted range (2-5%) and represents a **higher end** estimate. - This value would be plausible for the recurrence risk, but the question specifically asks for the *lower end*. *3%* - A 3% recurrence risk falls within the accepted range (2-5%) but is not the **lower end** of that range. - While a clinically relevant risk, it is not the minimum value requested in the question.

Q: Vasa previa is associated with which type of placental vessel insertion?

Velamentous. ***Velamentous*** - **Vasa previa** occurs when **fetal blood vessels** from a **velamentous cord insertion** cross the internal cervical os, unprotected by placental tissue or Wharton's jelly. - In a **velamentous insertion**, the umbilical cord inserts into the **chorioamniotic membranes** distant from the placental margin, with the vessels then coursing through the membranes to the placenta. *Central* - A **central placental vessel insertion** is the normal and healthy insertion point, typically near the center of the placenta. - This type of insertion is **not associated** with vasa previa, as the vessels are well-protected within the umbilical cord. *Peripheral* - A **peripheral placental vessel insertion** refers to the cord inserting at the margin of the placenta. - While considered marginal, it is **not directly associated** with vasa previa, which specifically involves vessels traversing unprotected membranes over the cervical os. *None of the options* - This option is incorrect because **velamentous cord insertion** is a direct and well-documented cause of vasa previa. - There is a specific and known association between velamentous insertion and vasa previa.

Q: Estimation of fetal hemoglobin is done by?

Kleihauer-Betke Acid Elution Test (KB Test). ***Kleihauer-Betke Acid Elution Test (KB Test)*** - The **Kleihauer-Betke test** is a widely used laboratory method to quantify the amount of **fetal hemoglobin** in a maternal blood sample. - This test is crucial in situations involving **fetomaternal hemorrhage** for calculating the dose of Rh immunoglobulin. *Apt test* - The Apt test is used to determine if blood in a **neonate's stool or vomitus** is of fetal or maternal origin. - It differentiates between **fetal hemoglobin (HbF)**, which is resistant to alkaline denaturation, and adult hemoglobin (HbA), which is not. *Flow cytometry* - **Flow cytometry** is a powerful technique used for sorting and counting cells, detecting **biomarkers**, and analyzing cell characteristics. - While it can be adapted to detect cells containing fetal hemoglobin (e.g., in research settings), it is not the primary or standard method for estimating the **total amount of fetal hemoglobin** in a sample for clinical purposes. *Spectrophotometry* - **Spectrophotometry** measures the absorption or transmission of light through a sample at different wavelengths. - It is used in many biochemical assays but is not the specific or sensitive method for **quantifying fetal hemoglobin** due to the similar absorption spectra of different hemoglobin types.

Q: Monozygotic twin with one healthy baby born at term and one dead mummified fetus is suggestive of?

Fetus papyraceous. ***Fetus papyraceous*** - This term describes a **mummified fetus** that has been flattened and compressed due to the growth of a co-twin, often observed in **monochorionic twin pregnancies** where one twin dies in utero. - The presence of one healthy, term baby and one dead, mummified fetus is the classic presentation of **fetus papyraceous**. *Fetus acardiacus* - This is a rare anomaly where one twin, typically in a **monochorionic-monoamniotic pregnancy**, lacks a functional heart and other upper body structures, relying on the healthy twin's circulation. - An acardiac twin would present as an underdeveloped, often malformed structure, not a mummified, flattened fetus. *Hydatidiform mole* - A **hydatidiform mole** is an abnormal pregnancy characterized by the growth of many cysts (grape-like vesicles) within the uterus, resulting from an issue with fertilization, often leading to a non-viable pregnancy. - It does not involve the presence of a healthy twin alongside a dead mummified one. *Vanishing twin* - **Vanishing twin syndrome** occurs when one of two or more embryos or fetuses in a multiple pregnancy dies and is completely reabsorbed by the mother or the surviving twin. - While it involves the death of a twin, the reabsorption typically means there's no mummified fetus remaining by the time of birth; if a remnant is found, it's typically much smaller and not described as "papyraceous."

Q: In a 34-week pregnancy with low-lying placenta previa and a floating head, with a hemoglobin level of 11 gm%, what should be the further line of management?

Expectant management. ***Expectant management*** - With a 34-week pregnancy, **placenta previa**, and no active bleeding or severe maternal/fetal compromise, **expectant management** is generally preferred to allow for fetal lung maturity. - The hemoglobin level of 11 gm% is within a reasonable range for pregnancy and does not immediately warrant intervention. *Induction of labor* - **Induction of labor** is contraindicated in placenta previa due to the risk of severe hemorrhage as the cervix dilates. - This approach would significantly endanger both the mother and the fetus. *Cesarean section* - While a **cesarean section** is likely the eventual mode of delivery for placenta previa, performing it at 34 weeks without evidence of fetal distress or active bleeding would be premature. - It would increase the risk of neonatal complications associated with prematurity. *Blood transfusion* - A hemoglobin level of **11 gm%** is considered mild anemia in pregnancy and does not typically warrant a **blood transfusion** unless there is active, significant blood loss or symptoms of severe anemia. - Transfusing blood without an immediate need carries its own risks.

Q: Which is the most common presentation in twin pregnancy?

Vertex - vertex. ***Vertex - vertex*** - This is the most common presentation in **twin pregnancies**, occurring in approximately **40-45%** of cases. - Both twins are positioned head-down, which is the optimal presentation for a vaginal delivery. *Vertex - breech* - This presentation, where the first twin is head-down and the second twin is feet- or buttocks-first, occurs in about **30%** of twin pregnancies. - While relatively common, it is still less frequent than the vertex-vertex presentation. *Breech - breech* - This presentation, where both twins are positioned feet- or buttocks-first, is less common, occurring in less than **10%** of twin pregnancies. - It usually necessitates a **cesarean section** due to increased risks associated with vaginal breech delivery for both twins. *Vertex - Footling* - **Footling breech** is a specific type of breech presentation where one or both feet present first. - While a vertex presentation for the first twin and a footling breech for the second twin can occur, it's a less common overall presentation for twin pairs compared to vertex-vertex.

Q: Clinical alarming sign of MgSO4 toxicity is?

Loss of knee jerk. ***Loss of knee jerk*** - **Magnesium sulfate (MgSO4)** toxicity manifests as central nervous system and neuromuscular depression. - The **knee jerk reflex** (patellar reflex) is one of the first deep tendon reflexes to be lost as magnesium levels approach toxic ranges, typically at serum levels of 7-10 mg/dL. *Loss of superficial abdominal reflexes* - Superficial reflexes are less sensitive indicators of impending **MgSO4 toxicity** compared to deep tendon reflexes. - While magnesium can cause muscle relaxation, the loss of these reflexes is not the primary or earliest clinical alarming sign. *Loss of pin prick sensation* - **Pinprick sensation** tests sensory pathways and is not directly affected by the neuromuscular blocking effects of magnesium sulfate. - Magnesium toxicity primarily affects motor function and deep tendon reflexes, not sensory perception. *Loss of proprioception* - **Proprioception** is the sense of joint position and movement, which is also a sensory function. - Magnesium toxicity does not typically cause a direct loss of proprioception; its effects are predominantly on motor nerve conduction and muscle contraction.

Q: What is the most common cause of death in babies with vasa previa?

Fetal exsanguination. ***Fetal exsanguination*** - In vasa previa, unprotected fetal blood vessels course directly over the **internal cervical os**. When the membranes rupture, these vessels are at high risk of tearing, leading to **rapid fetal blood loss**. - This acute hemorrhage results in **fetal exsanguination**, causing severe **anemia**, **hypoxia**, and ultimately **death** if not immediately identified and managed. *Infection* - While infection can arise in obstetric complications, it is **not the primary or most common cause of death** specifically associated with vasa previa. - The immediate and life-threatening danger in vasa previa is **acute blood loss**, not microbial invasion. *Maternal exsanguination* - Vasa previa primarily involves **fetal blood vessels** in the membranes, not maternal uterine vessels. - Therefore, the blood loss that occurs is almost exclusively fetal, and **maternal exsanguination is not a direct complication** of vasa previa. *Both maternal and fetal exsanguination* - As explained, vasa previa specifically endangers the fetus due to the exposed **fetal blood vessels**. - While fetal exsanguination is the critical event, **maternal exsanguination does not occur** as a direct result of vasa previa.

Q: What is the most common condition associated with a single umbilical artery?

Congenital heart disease. ***Congenital heart disease*** - Among major structural anomalies associated with a single umbilical artery (SUA), **congenital heart disease** is one of the most significant, occurring in approximately **15-20% of cases**. - Common cardiac defects include **ventricular septal defects (VSD)**, **atrial septal defects (ASD)**, and **coarctation of the aorta**. - SUA detected on prenatal ultrasound warrants **detailed fetal echocardiography** to rule out cardiac anomalies. - **Clinical significance**: Isolated SUA (without other anomalies) generally has a good prognosis, but cardiac evaluation is essential. *Neural tube defects (NTD)* - Neural tube defects are **not commonly associated** with single umbilical artery. - NTDs (such as spina bifida and anencephaly) are primarily linked to **folate deficiency** and have different screening markers including **elevated AFP** and direct ultrasound visualization. - The pathophysiology of NTDs is distinct from the vascular anomaly of SUA. *Fetal hydrops* - **Fetal hydrops** is a severe condition characterized by abnormal fluid accumulation in ≥2 fetal compartments (ascites, pleural effusion, pericardial effusion, skin edema). - While severe cardiac defects can lead to hydrops, **hydrops is not directly associated with SUA** as a primary finding. - Hydrops has multiple causes including severe anemia, cardiac failure, infections (TORCH), and chromosomal abnormalities. *Intrauterine fetal demise* - **IUFD is an adverse outcome**, not a congenital condition associated with SUA. - Isolated SUA has a **good prognosis** with only slightly increased perinatal risks when no other anomalies are present. - Risk of IUFD is elevated when SUA occurs with **multiple congenital anomalies** or **chromosomal abnormalities**, but IUFD itself is not the "condition associated with" SUA.

Question 1

What is the lower end of the estimated risk of recurrence of anencephaly in subsequent pregnancies?

Accepted Answer

2%

Answer

4%

Answer

1%

Answer

3%

Question 2

Vasa previa is associated with which type of placental vessel insertion?

Accepted Answer

Velamentous

Answer

Central

Answer

Peripheral

Answer

None of the options

Question 3

Estimation of fetal hemoglobin is done by?

Accepted Answer

Kleihauer-Betke Acid Elution Test (KB Test)

Answer

Apt test

Answer

Flow cytometry

Answer

Spectrophotometry

Question 4

Monozygotic twin with one healthy baby born at term and one dead mummified fetus is suggestive of?

Accepted Answer

Fetus papyraceous

Answer

Fetus acardiacus

Answer

Hydatidiform mole

Answer

Vanishing twin

Question 5

What is the recommended management for a fetus diagnosed with severe anemia in Liley's Zone 3 at 35 weeks of gestation?

Accepted Answer

Preterm delivery of the fetus

Answer

Intrauterine blood transfusion

Answer

Observation and follow-up

Answer

Cord blood sampling

Question 6

In a 34-week pregnancy with low-lying placenta previa and a floating head, with a hemoglobin level of 11 gm%, what should be the further line of management?

Accepted Answer

Expectant management

Answer

Cesarean section

Answer

Blood transfusion

Answer

Induction of labor

Question 7

Which is the most common presentation in twin pregnancy?

Accepted Answer

Vertex - vertex

Answer

Vertex - breech

Answer

Breech - breech

Answer

Vertex - Footling

Question 8

Clinical alarming sign of MgSO4 toxicity is?

Accepted Answer

Loss of knee jerk

Answer

Loss of superficial abdominal reflexes

Answer

Loss of pin prick sensation

Answer

Loss of proprioception

Question 9

What is the most common cause of death in babies with vasa previa?

Accepted Answer

Fetal exsanguination

Answer

Infection

Answer

Maternal exsanguination

Answer

Both maternal and fetal exsanguination

Question 10

What is the most common condition associated with a single umbilical artery?

Accepted Answer

Congenital heart disease

Answer

Neural tube defects (NTD)

Answer

Fetal hydrops

Answer

Intrauterine fetal demise

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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