To examine the relationship between antidepressant use in pregnancy and low birth weight (LBW) and preterm birth (PTB).

We searched English and non-English language articles via PubMed, CINAHL and PsychINFO (from their start dates through December 1st, 2012). We used the following keywords and their combinations: antidepressant, selective serotonin reuptake inhibitor (SSRI), pregnancy, antenatal, prenatal, birthweight, birth weight, preterm, prematurity, gestational age, fetal growth restriction, intrauterine growth restriction, and small-for-gestational age. Published studies were considered eligible if they examined exposure to antidepressant medication use during pregnancy and reported data on at least one birth outcome of interest: PTB (<37 weeks gestation) or LBW (<2500 g). Of the 222 reviewed studies, 28 published studies met the selection criteria.

Two authors independently extracted study characteristics from eligible studies.

Using random-effects models, antidepressant use in pregnancy was significantly associated with LBW (RR: 1.44, 95% confidence interval (CI): 1.21-1.70) and PTB (RR: 1.69, 95% CI: 1.52-1.88). Studies varied widely in design, populations, control groups and methods. There was a high level of heterogeneity as measured by I2 statistics for both outcomes examined. The relationship between antidepressant exposure in pregnancy and adverse birth outcomes did not differ significantly when taking into account drug type (SSRI vs. other or mixed) or study design (prospective vs. retrospective). There was a significant association between antidepressant exposure and PTB for different types of control status used (depressed, mixed or nondepressed).

Antidepressant use during pregnancy significantly increases the risk for LBW and PTB.