Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine Indian Medical PG Practice Questions and MCQs

Question 1291: A pregnant patient with a prosthetic valve on warfarin should be switched to heparin at

A. 36 weeks (Correct Answer)
B. Onset of labour
C. 30 weeks
D. 38 weeks

Explanation: ***36 weeks*** - At **36 weeks of gestation**, a pregnant patient on **warfarin** (due to a prosthetic valve) should be switched to **unfractionated heparin (UFH)** or **low molecular weight heparin (LMWH)**. - This timing is crucial to mitigate the risk of fetal coagulopathy from warfarin exposure during delivery and to allow for safer management of anticoagulation during labor and delivery. *30 weeks* - Switching to heparin at 30 weeks is generally too early and unnecessarily prolongs the period of subcutaneous injections, which can be burdensome for patients. - The primary concern of fetal coagulopathy with warfarin is highest closer to term, making a switch at 36 weeks more appropriate for balancing maternal and fetal risks. *38 weeks* - Switching at 38 weeks significantly increases the risk that labor might occur while the patient is still on warfarin, exposing the fetus to the drug and increasing the risk of maternal bleeding complications during delivery. - It leaves little buffer time for the warfarin's effects to wear off before spontaneous labor might begin. *Onset of labour* - Waiting until the onset of labor to switch from warfarin to heparin is dangerous and inappropriate. - Warfarin has a long half-life, and its anticoagulant effects would still be present during labor and delivery, posing a high risk of fetal hemorrhage (especially intracranial hemorrhage) and significant maternal bleeding.

Question 1292: In an Rh-negative mother who has delivered an Rh-positive baby, prophylactic anti-D is indicated for:

A. If the Indirect Coomb's test (ICT) is negative (Correct Answer)
B. If the Indirect Coomb's test (ICT) is positive (indicating sensitization)
C. If the Indirect Coomb's test (ICT) is positive with rising antibody titres
D. As a routine procedure for all Rh-negative mothers regardless of sensitization status

Explanation: ***If the Indirect Coomb's test (ICT) is negative*** - Prophylactic anti-D immunoglobulin works by **preventing active antibody production** in the mother when her immune system is first exposed to Rh-positive fetal red blood cells. - A **negative Indirect Coombs' test** indicates that the mother has not yet been sensitized and does not have pre-existing anti-Rh antibodies, making her an ideal candidate for prophylaxis. - This is the **key requirement** for anti-D administration to be effective. *If the Indirect Coomb's test (ICT) is positive (indicating sensitization)* - If the ICT is positive, it means the mother has already been **sensitized** and has produced antibodies against Rh-positive blood. - In this scenario, administering anti-D immunoglobulin would be ineffective as the **immune response has already occurred**. *If the Indirect Coomb's test (ICT) is positive with rising antibody titres* - A positive ICT with rising titers signifies that the mother is not only sensitized but also actively producing a **stronger immune response** against Rh-positive blood. - Anti-D immunoglobulin is a **preventative measure**, not a treatment for an active immune response, and would not be beneficial in this case. *As a routine procedure for all Rh-negative mothers regardless of sensitization status* - While anti-D is routinely recommended for non-sensitized Rh-negative mothers, it **must not be given without confirming negative sensitization status**. - Administering anti-D to already sensitized mothers (positive ICT) is ineffective and wasteful, as the immune response has already been established. - The ICT must be performed to **exclude prior sensitization** before prophylactic anti-D is given.

Question 1293: Which of the following is a known cause of breech presentation?

A. Septate uterus
B. Hydrocephalus
C. Hydramnios (Correct Answer)
D. Uterine fibroids

Explanation: ***Hydramnios*** - **Excessive amniotic fluid** (polyhydramnios) increases the space available for fetal movement, preventing the fetus from settling into a stable cephalic position - This allows **increased fetal mobility** and is a well-recognized cause of **malpresentation including breech presentation** - The lack of normal space constraints means the fetus can freely move and fail to engage in vertex position *Septate uterus* - **Uterine anomalies** including septate uterus can restrict the intrauterine space and are recognized causes of breech presentation - However, they are **less common** than other causes and may also lead to recurrent pregnancy loss or preterm delivery - While a valid cause, it's not as frequently encountered as polyhydramnios in clinical practice *Hydrocephalus* - **Fetal hydrocephalus** with enlarged head can prevent normal engagement of the fetal head in the maternal pelvis - This can lead to malpresentation, though the mechanism is more about **disproportion** preventing cephalic engagement rather than causing breech directly - It's a recognized but less common fetal factor compared to other causes *Uterine fibroids* - **Large uterine fibroids**, particularly those in the lower uterine segment, can obstruct fetal descent and cause malpresentation - They alter uterine cavity shape and can prevent normal version to cephalic presentation - However, they are a **less frequent** direct cause compared to conditions like polyhydramnios or oligohydramnios

Question 1294: What are the potential complications in subsequent pregnancies for a woman with a history of gestational trophoblastic disease?

A. Neural tube defects
B. Skeletal defects
C. Cardiac defects
D. Increased risk of recurrent GTD and pregnancy complications (Correct Answer)

Explanation: ***Increased risk of recurrent GTD and pregnancy complications*** - A history of **gestational trophoblastic disease (GTD)** significantly increases the risk of recurrence in subsequent pregnancies, emphasizing the need for close monitoring. - There is also an elevated risk of other **adverse pregnancy outcomes**, including **preterm birth** and **preeclampsia**, following a GTD history. *Neural tube defects* - **Neural tube defects** are congenital anomalies primarily associated with **folate deficiency** and genetic factors, not a prior history of GTD. - They involve incomplete closure of the neural tube during embryonic development, unrelated to trophoblastic tissue. *Cardiac defects* - **Congenital cardiac defects** are multifactorial, linked to genetic predisposition, maternal conditions like **diabetes**, and certain exposures, but not a history of GTD. - They result from abnormal heart development in the early stages of pregnancy. *Skeletal defects* - **Skeletal defects** can be hereditary or related to maternal infections (e.g., rubella), drug exposure (e.g., thalidomide), or specific genetic syndromes, not GTD. - These malformations occur during fetal bone and limb development.

Question 1295: Which of the following tests on amniotic fluid is most useful in distinguishing between open neural tube defects and ventral wall defects in a fetus?

A. Carcinoembryonic antigen
B. Alpha-fetoprotein
C. Sphingomyelin
D. Acetylcholinesterase (Correct Answer)

Explanation: ***Acetylcholinesterase*** - **Acetylcholinesterase (AChE)** is highly specific to neural tissue and its presence in amniotic fluid, combined with elevated AFP, is highly indicative of an **open neural tube defect (NTD)**. - While AFP is elevated in both NTDs and ventral wall defects, **AChE** helps differentiate by confirming neural tissue exposure. *Carcinoembryonic antigen* - **Carcinoembryonic antigen (CEA)** is a tumor marker primarily used in the diagnosis and monitoring of certain cancers, particularly colorectal cancer. - It has no established role in the prenatal diagnosis or differentiation of neural tube defects or ventral wall defects. *Sphingomyelin* - **Sphingomyelin** is a component of pulmonary surfactant and is measured to assess fetal lung maturity, usually in conjunction with lecithin as the **L/S ratio**. - This test is not used for the diagnosis or differentiation of structural birth defects like neural tube defects or ventral wall defects. *Alpha-fetoprotein* - **Alpha-fetoprotein (AFP)** is elevated in maternal serum and amniotic fluid in both **open neural tube defects** and **ventral wall defects** (e.g., gastroschisis, omphalocele). - While useful for screening, **AFP alone cannot distinguish** between these two conditions, as it is non-specific for the type of open defect.

Question 1296: The weight of the placenta at term is

A. 250 gm
B. 500 gm (Correct Answer)
C. 1000 gm
D. 750 gm

Explanation: ***Correct: 500 gm*** - The average weight of a full-term placenta is approximately **500 grams (1 pound)**. - This weight is typically about **one-sixth of the baby's weight** at term. - Normal range is approximately **450-650 grams**. *Incorrect: 250 gm* - A placenta weighing 250 grams at term would be considered **abnormally small** and could indicate **placental insufficiency** or other complications. - A smaller placenta may not be able to adequately support fetal growth and development. *Incorrect: 750 gm* - A placenta weighing 750 grams at term would be considered **abnormally large**, potentially indicating conditions like **maternal diabetes**, **fetal hydrops**, or **placental edema**. - This represents a significantly enlarged placenta beyond the normal range. *Incorrect: 1000 gm* - A placenta weighing 1000 grams (1 kg) at term would be considered **markedly enlarged**, potentially indicating severe conditions like **maternal diabetes**, **fetal hydrops**, **infection**, or **placentomegaly**. - While larger than average, such weights can occur in pathological pregnancies but are far from the normal 500g in a healthy pregnancy.

Question 1297: Which of the following statements regarding cholestasis in pregnancy is false?

A. Ursodeoxycholic acid relieves pruritus
B. Recurs in subsequent pregnancy
C. Mild jaundice occurs in majority of patients (Correct Answer)
D. Pruritus is the most common symptom of cholestasis in pregnancy

Explanation: ***Mild jaundice occurs in majority of patients*** - This statement is **false** because while **pruritus** is a hallmark symptom of **intrahepatic cholestasis of pregnancy (ICP)**, **jaundice** is relatively uncommon, occurring in only **10-25%** of patients, typically those with more severe disease. - The primary clinical manifestation is intense itching, often without visible signs of jaundice. *Recurs in subsequent pregnancy* - **Cholestasis in pregnancy** has a **high recurrence rate**, estimated to be between **45% to 90%** in subsequent pregnancies. - This tendency for recurrence highlights a possible genetic predisposition or hormonal sensitivity. *Ursodeoxycholic acid relieves pruritus* - **Ursodeoxycholic acid (UDCA)** is the **first-line treatment** for cholestasis in pregnancy and is effective in improving biochemical markers and relieving **pruritus**. - It works by altering the bile acid composition, making them less toxic and facilitating their excretion. *Pruritus is the most common symptom of cholestasis in pregnancy* - **Pruritus** is indeed the **most common and prominent symptom** of ICP, occurring in virtually all patients. - Some patients may also experience **fatigue**, **nausea**, **dark urine**, **pale stools**, or **steatorrhea**, although these are less common. - It is also associated with fetal risks such as **preterm birth**, **stillbirth**, and **fetal distress**, which are important complications of the condition.

Question 1298: A 26-year-old gravida 3 woman has a history of gestational diabetes and a delivery of two previous infants at term that were greater than 4000 grams, each of whom had severe hypoglycemia. Which of the following maneuvers is least likely to reduce the chance of the next child's having hypoglycemia?

A. Careful glucose monitoring of the infant
B. Careful control of the maternal blood glucose levels during pregnancy
C. Maternal intravenous loading with 10% glucose beginning 2 to 4 h prior to the expected time of delivery (Correct Answer)
D. Early feedings of the infant

Explanation: ***Maternal intravenous loading with 10% glucose beginning 2 to 4 h prior to the expected time of delivery*** - Administering a **glucose bolus** to the mother prior to delivery would increase maternal glucose levels, subsequently leading to **fetal hyperglycemia** and an increase in fetal insulin production. - Upon delivery, the infant's continued high insulin levels in the presence of interrupted maternal glucose supply would **exacerbate neonatal hypoglycemia** rather than reduce it. *Careful control of the maternal blood glucose levels during pregnancy* - **Strict glycemic control** throughout pregnancy reduces fetal exposure to high glucose levels, which helps prevent fetal pancreatic beta-cell hyperplasia and excessive insulin production. - This effectively lowers the risk of **neonatal hypoglycemia** and macrosomia, as the fetus is less likely to develop hyperinsulinemia. *Careful glucose monitoring of the infant* - **Early and frequent monitoring** of the infant's blood glucose levels allows for prompt detection of hypoglycemia. - This enables timely intervention through feeding or intravenous glucose administration, thereby **preventing severe or prolonged hypoglycemia** and its associated complications. *Early feedings of the infant* - Providing **early and frequent feedings** (breast milk or formula) supplies the infant with essential glucose, helping to stabilize blood sugar levels. - This is particularly crucial for infants of diabetic mothers who are at higher risk for hypoglycemia due to **perinatal hyperinsulinemia**.

Question 1299: Alpha-fetoproteins are not increased in which of the following conditions?

A. Omphalocele
B. Anencephaly
C. Spina bifida
D. Post maturity (Correct Answer)

Explanation: ***Correct: Post maturity*** - In **post-maturity**, the fetus continues to develop past the expected due date (>42 weeks) - **Alpha-fetoprotein (AFP)** levels are **not elevated** in post-term pregnancies - AFP levels may actually decline as pregnancy progresses beyond term - Post-maturity is associated with placental insufficiency, not AFP elevation *Incorrect: Spina bifida* - **Spina bifida** is an **open neural tube defect** where the spinal cord is exposed - Leads to direct leakage of AFP into the amniotic fluid and maternal serum - Causes **significantly elevated AFP levels** (typically >2.5 MoM) *Incorrect: Omphalocele* - **Omphalocele** is an **abdominal wall defect** where abdominal organs herniate through the umbilicus - Covered by a membrane, but still allows AFP leakage - Associated with **elevated maternal serum AFP levels** - AFP elevation is less pronounced than with neural tube defects *Incorrect: Anencephaly* - **Anencephaly** is a severe **open neural tube defect** with absence of major portions of the brain and skull - Results in direct exposure of neural tissue to amniotic fluid - One of the **most common causes of markedly elevated AFP** (often >3-4 MoM) - Almost always detectable by elevated maternal serum AFP screening

Question 1300: Sonography of a term multigravida shows an amniotic fluid index of 3 cm. The fetus may have which condition?

A. Esophageal atresia
B. Spina bifida
C. Chorioangioma of the placenta
D. Renal agenesis (Correct Answer)

Explanation: ***Renal agenesis*** - An **Amniotic Fluid Index (AFI)** of 3 cm indicates **oligohydramnios**, which is a severely reduced amount of amniotic fluid. - **Fetal urine production** is a major source of amniotic fluid in the second half of pregnancy, and conditions like renal agenesis or severe renal obstruction prevent urine formation, leading to oligohydramnios. *Esophageal atresia* - This condition is associated with **polyhydramnios** (excess amniotic fluid) because the fetus cannot swallow the amniotic fluid. - Oligohydramnios is typically not seen with esophageal atresia. *Spina bifida* - **Neural tube defects** like spina bifida are not typically associated with oligohydramnios. - They are sometimes linked to **polyhydramnios** if there is impaired fetal swallowing due to brainstem involvement, or normal amniotic fluid levels. *Chorioangioma of the placenta* - A **chorioangioma** is a benign placental tumor that can rarely cause **polyhydramnios** due to increased blood flow to the tumor, leading to increased transudation of fluid. - It would not lead to **oligohydramnios**.

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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