Single bolus low-dose of ketamine does not prevent postpartum depression: a randomized, double-blind, placebo-controlled, prospective clinical trial

Postpartum depression is a common complication of childbirth. In the last decade, it has been suggested that subdissociative-dose ketamine is a fast-acting antidepressant. We aimed to investigate the efficacy of low-dose ketamine administered during caesarean section in preventing postpartum depression.Using a randomized, double-blind, placebo-controlled design, 330 parturients who were scheduled to undergo caesarean section were enrolled in this trial. The parturients were randomly assigned to receive intravenous ketamine (0.25 mg/kg diluted to 10 mL with 0.9% saline) or placebo (10 mL of 0.9% saline) within 5 min following clamping of the neonatal umbilical cord. The primary outcome was the degree of depression, which was evaluated using the Edinburgh Postnatal Depression Scale (EPDS) (a threshold of 9/10 was used) at 3 days and 6 weeks after delivery. The secondary outcome was the numeric rating scale score of pain at 3 day and 6 week postpartum.No significant differences were found in the prevalence of postpartum depression between the two groups at 3 days and 6 weeks after delivery. The pain scores measured at 3 days postoperatively were not significantly different between the groups, whereas the scores measured at 6 week postpartum were significantly reduced in the treatment group compared with the saline group (P = 0.014).Intra-operative low-dose ketamine (0.25 mg/kg) does not have a preventive effect on postpartum depression.