Antidepressant use in late gestation and risk of postpartum haemorrhage: a retrospective cohort study.

Abstract

To investigate the association between antidepressant use in late gestation and postpartum haemorrhage (PPH). Retrospective cohort study. Tertiary teaching hospital in Adelaide, Australia. A total of 30198 women delivering between 2002 and 2008. Relative risks adjusted for maternal sociodemographics and comorbidities (aRRs) were calculated for PPH, comparing women with late-gestation exposure to antidepressants (n=558), women with a psychiatric illness but no antidepressant use (n=1292), and women with neither antenatal exposures (n=28348). Additional sensitivity analyses were undertaken, examining associations with severe PPH and postpartum anaemia. The primary outcome was PPH, defined as a recorded blood loss of ≥500mL for vaginal deliveries and ≥1000mL for caesarean sections. Secondary outcomes included severe PPH (≥1000mL blood loss, irrespective of method of delivery), and the presence of postpartum anaemia (identified from hospital medical records). Compared with unexposed controls, women exposed to antidepressants had an increased risk of PPH (aRR1.53; 95% confidence interval, 95%CI 1.25-1.86), whereas no increased risk was observed for women with a psychiatric illness but no antidepressant use (aRR1.04; 95%CI 0.89-1.23). In sensitivity analyses, late gestation antidepressant exposure was associated with an increased risk of severe PPH (aRR1.84; 95%CI 1.39-2.44), as well as postpartum anaemia (aRR1.80; 95%CI1.46-2.22). Exposure to antidepressants in late gestation was associated with a significantly increased risk of PPH. Although potential confounding by unmeasured factors cannot be ruled out, these findings suggest a direct effect of antidepressant exposure on PPH. Late gestation antidepressant exposure is associated with a significantly increased risk of postpartum haemorrhage.