There are data to support the use of certain antidepressants during pregnancy. Most of the research over the last decade has focused on the selective serotonin reuptake inhibitors (SSRIs) like fluoxetine (Prozac) and the older tricyclic antidepressants, but there is some new data supporting the use of bupropion during pregnancy.

The most recent information from the Bupropion Pregnancy Registry maintained by the manufacturer GlaxoSmithKline includes data from 517 pregnancies involving first trimester exposure to bupropion. In this sample, there were 20 infants with major malformations. This represents a 3.9% risk of congenital malformation that is consistent with what is observed in women with no known teratogen exposure. (Health care providers may receive an updated report from GlaxoSmithKline by calling (800) 336-2176.) While this information regarding the overall risk of malformation is reassuring, earlier reports had revealed an unexpectedly high number of malformations of the heart and great vessels in bupropion-exposed infants.

To more carefully quantify the risk for cardiovascular malformation in bupropion-exposed infants, another study was conducted relying upon two large insurance claims databases (Cole et al, 2006). Outcomes were compared in three different groups: (1) women dispensed bupropion during the first trimester, (2) women dispensed other antidepressant during the first trimester, and (3) women dispensed bupropion after the first trimester. This retrospective cohort study including over 1200 infants exposed to bupropion during the first trimester did not reveal an increased risk of malformations in the bupropion-exposed group of infants nor did it demonstrate an increased risk for cardiovascular malformations. This study, however, did observe an increased risk of cardiovascular malformation in paroxetine-exposed infants (see our eNewsletter December 2005).

These data are complemented by a smaller prospective study from the Motherisk Program in Toronto (Chun-Fai-Chan et al, 2005). Women who were pregnant or planning a pregnancy and taking bupropion (n=136) were enrolled in the study and were contacted after delivery. There were 105 live births and no major malformations were reported. Compared to a group of women with non-teratogen exposures, there were no significant differences in birth weight or mean gestational age. In the bupropion group 20 women (14.7%) had miscarriages, which is higher than observed in the non-teratogen control group but is consistent with rates observed in women taking other antidepressants.

Given these data, bupropion may be an attractive option for women who have not responded well to fluoxetine or tricyclic antidepressants. Further studies are required to assess the risk of neonatal symptoms in bupropion-exposed infants and to better evaluate the long-term neurobehavioral effects of bupropion exposure.

Ruta Nonacs, MD PhD

Up-to-date information on Paroxetine (and other related antidepressants) and pregnancy via GlaxoSmithKline: http://www.gsk.com/en-gb/media/resource-centre/paroxetine/paroxetine-and-pregnancy/

Chun-Fai-Chan B, Koren G, Fayez I, Kalra S, Voyer-Lavigne S, Boshier A, Shakir S, Einarson A. Pregnancy outcome of women exposed to bupropion during pregnancy: a prospective comparative study. Am J Obstet Gynecol, March 2005. 192(3).

Cole JA, Modell JG, Haight BR, Cosmatos IS, Stoler JM, Walker AM. Bupropion in pregnancy and the prevalence of congenital malformations. Pharmacoepidemiol Drug Saf. 9 August 2006