There has been concern that exposure to lithium early in pregnancy may be associated with a marked increase in the risk of Ebstein’s anomaly (a right ventricular outflow tract obstruction defect) in infants and overall congenital cardiac defects, but data are conflicting and limited | NEJM
Methods: We conducted a cohort study involving 1,325,563 pregnancies in women who were enrolled in Medicaid and who delivered a live-born infant between 2000 and 2010. We examined the risk of cardiac malformations among infants exposed to lithium during the first trimester as compared with unexposed infants and, in secondary analyses, with infants exposed to another commonly used mood stabilizer, lamotrigine. Risk ratios and 95% confidence intervals were estimated with control for psychiatric and medical conditions, medications, and other potential confounders.
Conclusions: Maternal use of lithium during the first trimester was associated with an increased risk of cardiac malformations, including Ebstein’s anomaly; the magnitude of this effect was smaller than had been previously postulated
Full reference: Patorno, E. et al. (2017) Lithium Use in Pregnancy and the Risk of Cardiac Malformations. New England Journal of Medicine. 376 pp. 2245-2254