Selective Serotonin Reuptake Inhibitor Use in Pregnancy and Risk of Postpartum Hemorrhage

Selective serotonin reuptake inhibitors (SSRIs) may predispose to postpartum hemorrhage (PPH) by interfering with platelet-mediated hemostasis and serotonin-mediated myometrial contractility. A meta-analysis of 8 observational studies found that, regardless of drug class, gestational exposure to antidepressants was associated with a small (odds ratio, 1.25) but statistically significantly increased risk of PPH; however, this finding was true only when antidepressant exposure was proximal to the date of delivery. A recent, moderately large, nationally representative, Swedish observational study also found that gestational exposure to SSRIs was associated with a significantly increased risk of PPH; the crude number needed to harm was 48. For reasons related to the methodology employed, it is possible that the risk was underestimated in this study. The findings of the meta-analysis and of the observational study are examined with a view to help readers understand how to critically read and interpret the research literature in the field. A reasonable viewpoint is that the increase in risk of PPH associated with gestational exposure to SSRIs is smaller than the increase in risk associated with obstetric risk factors for PPH; nevertheless, following precautionary measures would be wise. Such measures would include the routine administration of a uterotonic agent immediately after delivery to all women who have received serotonin reuptake inhibitor treatment during the month preceding delivery; the choice of uterotonic agent would depend on local hospital protocols. Women at risk should also be closely monitored for continued blood loss during the first 24 hours after delivery.