What are the primary effects of lithium exposure during pregnancy?

Lithium exposure during pregnancy is most notably associated with Ebstein anomaly, which is a congenital heart defect that affects the tricuspid valve and the right side of the heart. This condition occurs due to abnormal development of the tricuspid valve, leading to issues with blood flow in the heart. Maternal exposure to lithium, particularly during the first trimester when organogenesis occurs, has been shown through various studies to increase the risk of this specific anomaly in newborns.

Other potential birth defects related to cardiac development are also of concern with different teratogenic exposures, but Ebstein anomaly is the most strongly linked to lithium. This association is significant enough that healthcare providers often monitor women who require lithium for psychiatric conditions closely during pregnancy, considering alternative treatments based on the potential risks.

The other choices, while they describe various congenital conditions, are not primarily associated with lithium exposure. Increased muscle tone may relate to other factors, but is not specifically linked to lithium. Caudal regression syndrome and transposition of the great arteries have different etiologies and associations than those generally attributed to lithium usage during pregnancy. Consequently, recognizing that Ebstein anomaly is a primary effect of lithium exposure underscores the importance of careful risk-benefit analysis in treating pregnant patients with bipolar disorder or other