Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is a major risk factor for Ebstein's anomaly during pregnancy?

1. Mother's obesity

2. Mother using tobacco

3. Mother taking lithium

4. Father's family history

The correct answer is: Mother taking lithium

The major risk factor for Ebstein's anomaly during pregnancy is the mother's use of lithium. Ebstein's anomaly is a congenital heart defect that affects the tricuspid valve and the right side of the heart, and its association with lithium is significant due to the teratogenic effects that lithium can have during the first trimester of pregnancy. Lithium, commonly used to treat bipolar disorder, has been linked to various cardiac anomalies in the offspring when exposure occurs during critical periods of heart development. The other options, while they may contribute to a range of adverse outcomes in pregnancy, are not specifically recognized as major risk factors for Ebstein's anomaly. For instance, maternal obesity and tobacco use are known to increase the risk of general pregnancy complications and may lead to other health issues in the baby but have not been directly linked to the development of Ebstein's anomaly. Similarly, a father's family history may indicate a genetic predisposition to certain conditions, but without maternal exposure to teratogens like lithium, the chances of such a specific defect occurring are not significantly elevated.