Weight gain in breastfed infants of mothers taking antidepressant medications.

Background: Little is known about the physical development of infants who are exposed to antidepressant medications through breast milk.

Method: Seventy-eight breastfeeding women taking antidepressant medications were included in the study. Maternal mood was prospectively evaluated at 6, 12, and 18 months postpartum. Infants' weights were obtained from review of pediatric records. Data were gathered from 1997 to 2002.

Results: Infants' weights were not significantly different from weights of 6-month-old breastfed infants from normative populations. However, infants of mothers who relapsed to relatively long-lasting major depressive episodes (lasting 2 months or more) following delivery weighed significantly (p =.002) less when compared with infants of mothers who relapsed to brief depressive episodes (< 2 months) and infants of mothers who did not relapse to depression in the postpartum period. This finding remained after including medication dosage and infant birth weight as covariates.

Conclusion: Exposure to antidepressant medications through breast milk does not appear to affect infants' weight. However, infants exposed to maternal depression lasting 2 months or more appear to experience significantly lower weight gain than infants of euthymic mothers or mothers who experience brief (< 2 months) major depressive episodes. Maternal depression following delivery may influence behaviors that, over the course of 2 months or more, affect infants' weight gain.