Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 1201: What is the most common cause of death in babies with vasa previa?

A. Infection
B. Maternal exsanguination
C. Fetal exsanguination (Correct Answer)
D. Both maternal and fetal exsanguination

Explanation: ***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.

Question 1202: What is the typical placenta-to-baby weight ratio at term?

A. 1 : 3
B. 1 : 4
C. 1 : 5
D. 1 : 6 (Correct Answer)

Explanation: ***1 : 6*** * The placenta-to-baby weight ratio at term is typically 1:6, meaning the placenta weighs approximately one-sixth of the baby's weight. * This ratio reflects the normal physiological balance required for adequate **fetal growth** and **nutrient exchange**. *1 : 3* * A 1:3 ratio would imply a proportionally much **larger placenta** relative to the baby's weight, which is not typical at term. * Such a ratio might be seen in cases of placental abnormalities or fetal growth restriction, but not as a normal physiological state. *1 : 4* * A 1:4 ratio indicates a **larger placenta** than physiologically normal at term, suggesting potential placental issues. * This is not the standard ratio observed in healthy pregnancies at term. *1 : 5* * While closer to the normal range than 1:3 or 1:4, a 1:5 ratio still suggests a slightly **larger placenta** than average. * The most commonly accepted healthy average at term is 1:6.

Question 1203: What is the most common condition associated with a single umbilical artery?

A. Neural tube defects (NTD)
B. Fetal hydrops
C. Congenital heart disease (Correct Answer)
D. Intrauterine fetal demise

Explanation: ***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 1204: What is the recommended management for intrauterine hydronephrosis detected at 32-34 weeks of gestation?

A. Intrauterine drainage
B. Immediate delivery
C. Serial USG monitoring and evaluation for associated anomalies (Correct Answer)
D. Postnatal evaluation at 3 weeks

Explanation: ***Serial USG monitoring and evaluation for associated anomalies*** - For **intrauterine hydronephrosis** detected at 32-34 weeks, **serial ultrasonography (USG)** is the recommended approach to monitor progression and severity. - This allows for the evaluation of associated anomalies (e.g., **posterior urethral valves, multicystic dysplastic kidney**) and helps in planning postnatal management. *Intrauterine drainage* - **Intrauterine drainage** (e.g., vesicoamniotic shunt) is generally reserved for severe cases of **bilateral obstructive uropathy** causing **oligohydramnios** and potential lung hypoplasia, which is not indicated here. - This intervention carries significant risks and is usually considered only when the benefits strongly outweigh the potential complications. *Postnatal evaluation at 3 weeks* - **Waiting until 3 weeks** postnatally without any monitoring during the late prenatal period is not an appropriate management strategy. - This could lead to a missed opportunity for early detection of worsening hydronephrosis or the development of complications before birth. *Immediate delivery* - **Immediate delivery** is typically indicated only in cases of severe, progressive hydronephrosis causing **fetal compromise** or **oligohydramnios** refractory to other interventions. - At 32-34 weeks, the risks associated with preterm delivery would generally outweigh the benefits unless there is a critical and worsening fetal condition.

Question 1205: What is the approximate fetal weight to placental weight ratio at 24 weeks of gestation?

A. 1.5:1
B. 3:1
C. 4:1
D. 2:1 (Correct Answer)

Explanation: ***2:1*** - The fetal weight to placental weight ratio at **24 weeks of gestation** varies across different references, with this ratio being cited in some older literature. - However, **current obstetric literature** suggests the ratio at 24 weeks is typically **higher (approximately 5:1 to 6:1)**, as the fetus (600-700g) significantly outweighs the placenta (100-120g) by this stage. - At 24 weeks, the fetus undergoes **rapid growth**, while placental growth rate has stabilized, leading to an increasing fetal-to-placental weight ratio. *1.5:1* - This ratio suggests the **fetus is only slightly heavier** than the placenta. - Such a ratio is typically observed **earlier in pregnancy (around 16-18 weeks)**, when placental mass is still relatively large compared to fetal mass. *3:1* - This ratio would indicate the fetus is **three times heavier** than the placenta. - While closer to physiologic values at 24 weeks, this still **underestimates** the typical fetal-to-placental weight ratio at this gestational age. *4:1* - This ratio suggests the fetus is **four times heavier** than the placenta. - This is **more consistent with mid-to-late second trimester** values and approaches the expected range, though current evidence suggests even higher ratios (5-6:1) at 24 weeks. **Note:** The fetal-to-placental weight ratio progressively increases throughout pregnancy, starting below 1:1 in early pregnancy and reaching 6-7:1 at term. Standard teaching suggests ratios of 5-6:1 at 24 weeks, though variation exists across references.

Question 1206: Which of the following is NOT a common cause of maternal death in patients with hypertensive disorders of pregnancy?

A. Cardiac failure
B. ARDS
C. Cerebral hemorrhage
D. Chronic renal failure (Correct Answer)

Explanation: ***Chronic renal failure*** - While chronic kidney disease can worsen during pregnancy and complicate hypertensive disorders, it is **NOT a common direct cause of maternal death** in hypertensive disorders of pregnancy. - The acute complications that arise (such as **acute kidney injury**, **eclampsia**, or **severe pre-eclampsia**) are the actual life-threatening events, rather than pre-existing chronic renal failure itself. - In contrast to the other options listed, **chronic renal failure** as a primary cause of maternal mortality is significantly less frequent in the setting of hypertensive disorders of pregnancy. *Cardiac failure* - **Pre-eclampsia** and **eclampsia** significantly increase cardiac workload and can lead to **acute heart failure**, especially with pre-existing cardiac disease or severe hypertension. - This is a **well-recognized and common cause** of maternal death in patients with severe hypertensive disorders of pregnancy. *ARDS* - **Acute Respiratory Distress Syndrome (ARDS)** is a severe complication of **pre-eclampsia** and **eclampsia**, often due to pulmonary edema from capillary leak and fluid overload. - It is a **critical and potentially fatal** respiratory complication representing one of the common causes of maternal death in severe hypertensive disorders. *Cerebral hemorrhage* - **Severe hypertension** in **pre-eclampsia** and **eclampsia** can lead to hemorrhagic stroke. - **Cerebral hemorrhage** is a **leading cause of maternal mortality** in women with severe hypertensive disorders of pregnancy, particularly eclampsia.

Question 1207: Which is the most common presentation in twin pregnancy?

A. Vertex - vertex (Correct Answer)
B. Vertex - breech
C. Breech - breech
D. Vertex - Footling

Explanation: ***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.

Question 1208: Risk period for maximum fetal damage due to congenital rubella infection?

A. First trimester of pregnancy (Correct Answer)
B. Second trimester of pregnancy
C. Third trimester of pregnancy
D. Risk is same throughout the pregnancy

Explanation: ***First trimester of pregnancy*** - The **organogenesis** phase occurs predominantly in the first trimester, making the developing fetus highly vulnerable to teratogens like the **rubella virus**. - Infection during this period (especially **weeks 1-12**) leads to the highest incidence and most severe forms of **congenital rubella syndrome (CRS)**, affecting major organs such as the heart, eyes, and brain. *Second trimester of pregnancy* - While fetal infection can still occur, the risk of severe congenital anomalies significantly decreases as most major organs have already formed. - Infections in the second trimester are more likely to result in **fetal growth restriction** or later-onset defects rather than the classic CRS triad. *Third trimester of pregnancy* - Infection during the third trimester typically carries a very low risk of congenital malformations. - The primary concern during this period is **perinatal transmission** leading to neonatal infection rather than structural birth defects. *Risk is same throughout the pregnancy* - This statement is incorrect because the vulnerability of the fetus to rubella virus varies greatly depending on the stage of development, with the **first trimester** being the most critical period. - The developing organs in early pregnancy are far more susceptible to damage from viral replication and inflammation.

Question 1209: Spalding sign is seen in ?

A. Drowning
B. Mummification
C. Maceration (Correct Answer)
D. Starvation

Explanation: ***Maceration*** - **Spalding sign** is a classic radiological finding in **intrauterine fetal death**, characterized by the **overlapping of fetal skull bones** due to liquefaction of the brain and loss of structural support. - This sign typically appears **7-10 days after fetal demise** and is a hallmark of **maceration**, the aseptic autolysis of a dead fetus retained in utero in the presence of amniotic fluid. - Maceration involves softening and peeling of skin, reddish discoloration, and progressive tissue breakdown in a **moist intrauterine environment**. *Mummification* - **Mummification** is an alternative form of fetal death in utero that occurs in **dry conditions** (typically in twin pregnancies where one twin dies and amniotic fluid is absent). - The fetus becomes **desiccated, shriveled, and preserved** rather than undergoing liquefaction. - Spalding sign is **not seen** in mummification because the skull remains intact without liquefactive changes. *Drowning* - **Drowning** is death by suffocation in a liquid medium and is unrelated to intrauterine fetal pathology. - Not associated with Spalding sign, which is specific to retained dead fetus in utero. *Starvation* - **Starvation** refers to severe nutritional deprivation leading to wasting and organ failure. - Not associated with specific radiological signs of fetal death like Spalding sign.

Question 1210: What are the potential effects of amphetamine use during pregnancy?

A. Intrauterine growth restriction (IUGR)
B. Cardiac anomalies
C. Cleft lip
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - Amphetamine use during pregnancy is associated with a wide range of adverse outcomes due to its **vasoconstrictive** and **teratogenic** effects. - This includes increased risks of **intrauterine growth restriction (IUGR)**, **cardiac anomalies**, and **cleft lip/palate**. *Intrauterine growth restriction (IUGR)* - Amphetamines cause **vasoconstriction**, which can reduce blood flow to the placenta and fetus, leading to **poor nutrient and oxygen delivery** and subsequent IUGR. - While IUGR is a significant risk, it is not the sole potential effect of amphetamine exposure. *Cardiac anomalies* - Amphetamines can disrupt early fetal development, specifically leading to an increased incidence of various **congenital heart defects**. - These cardiac malformations are just one component of the broader spectrum of anomalies associated with amphetamine exposure. *Cleft lip* - Maternal amphetamine use is linked to **craniofacial malformations**, including **cleft lip** and **cleft palate**, likely due to the drug's impact on neural crest cell migration and development. - This specific birth defect is among several potential structural abnormalities that can occur.

Practice by Chapter

Fetal Assessment Techniques

Practice Questions

Hypertensive Disorders in Pregnancy

Practice Questions

Intrauterine Growth Restriction

Practice Questions

Multiple Gestation

Practice Questions

Rh Isoimmunization and Other Blood Group Incompatibilities

Practice Questions

Intrauterine Fetal Therapy

Practice Questions

Prenatal Diagnosis and Genetic Counseling

Practice Questions

Placental Abnormalities

Practice Questions

Preterm Labor and Delivery

Practice Questions

Management of Medical Disorders in Pregnancy

Practice Questions

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