Serum Valproate Levels in 6 Breastfeeding Mother-Infant Pairs

Background: Women with bipolar disorder are at high risk for recurrence of an affective episode in the postpartum period, and treatment with a mood stabilizer may be indicated. Few data are available to inform the risk-benefit decision regarding the use of valproate for women with bipolar disorder who elect to breast-feed.

Method: Serum valproate levels were obtained from 6 breastfeeding mother-infant pairs. All mothers had a diagnosis of bipolar disorder (Research Diagnostic Criteria) and were taking divalproex sodium as prophylaxis for or treatment of a recurrent affective episode. None of the mothers received valproate during pregnancy.

Results: The mothers had serum valproate levels near or within the therapeutic range (39.4 to 79.0 microg/mL). Infant serum levels were low, ranging from 0.7 to 1.5 microg/mL (0.9%-2.3% of maternal serum levels). No adverse clinical effects were observed in the infants.

Conclusion: Serum valproate levels were low in nurslings of mothers treated with valproate. These data can be used to inform clinical decisions regarding the use of valproate during breastfeeding.