Lithium Use in Early Pregnancy Linked to Congenital Cardiac Defects

A US cohort study suggested that maternal use of lithium during the first trimester was associated with an increased risk of cardiac malformations, including Ebstein’s anomaly (right ventricular outflow tract obstruction defects). The study included 1,325,563 pregnancies in women who delivered a live-born infant between 2000 and 2010. Cardiac malformations were present in 16 of the 663 infants exposed to lithium (2.41%), 15,251 of the 1,322,955 nonexposed infants (1.15%), and 27 of the 1945 infants exposed to lamotrigine (another commonly used mood stabilizer, 1.39%). The adjusted risk ratio (RR) for cardiac malformations among infants exposed to lithium as compared with unexposed infants was 1.65. The RR was 1.11 for a daily dose of 600 mg or less, 1.60 for 601 to 900 mg, and 3.22 for more than 900 mg. The prevalence of right ventricular outflow tract obstruction defects was 0.60% among lithium-exposed infants versus 0.18% among unexposed infants (adjusted RR, 2.66). Results were similar when lamotrigine-exposed infants were used as the reference group. Source: http://www.nejm.org/