Abstract 427 Poster Session IV, Tuesday, 5/4 (poster 201)

Objective: To separate the effects of tricyclic antidepressant drugs (TCA) and fluoxetine taken during pregnancy on measures of perinatal outcome, from the effects of maternal depression and other confounders.

Methods: A prospective, controlled, observational study of mother-child pairs exposed in utero to TCA, fluoxetine and an unexposed comparison group. The statistical model adjusted for independent variables which may affect the outcomes of interest, including length of therapy (first trimester vs. throughout pregnancy), smoking, socioeconomic class, and severity of depression.

Results: Neither TCA nor fluoxetine taken either during the first trimester or throughout pregnancy, affected birth weight, gestational age, or the risk for neonatal complications when severity of maternal depression was considered in the model. Without controlling for the severity of maternal depression, birth weight was affected by antidepressant therapy. These observations are explained by the fact that women who continued fluoxetine throughout gestation had significantly more severe depression.

Conclusions: TCAs and fluoxetine do not appear to increase by themselves fetal risk for prematurity, lower birth weight or perinatal complications. Conversely, the level of clinical depression does appear to affect fetal well being.

Recommendations: Women who need either TCAs or fluoxetine during pregnancy should be treated with adequate doses to control the severity of their depression, which may affect fetal outcome.

Supported by grants from MRC-PMAC (Canada), and The Motherisk Program Research Fund. IN is supported by a Fellowship from Lilly's Center for Women's Health, Indianapolis, Indiana.