RESUMO
Background: Cesarean section (CS) has been linked to a number of negative effects, such as pain, anxiety, and sleeping problems. The aim of this systematic review and meta-analysis was to investigate the safety and efficacy of preoperative melatonin on postoperative outcomes in pregnant women who were scheduled for elective CS. Methods: We systemically searched 4 electronic databases (PubMed, Scopus, Web of Science, and Cochrane Library) from inception until 10 March 2023. We included randomized controlled trials (RCTs) comparing melatonin and placebo for postoperative outcomes in CS patients. For risk of bias assessment, we used the Cochrane Risk of Bias 2 tool. Continuous variables were pooled as mean difference (MD), and categorical variables were pooled as a risk ratio (RR) with a 95% confidence interval (CI). Results: We included 7 studies with a total of 754 pregnant women scheduled for CS. The melatonin group had a lower pain score (MD = -1.23, 95% CI [-1.94, -0.51], p < 0.001) and longer time to first analgesic request (MD = 60.41 min, 95% CI [45.47, 75.36], p < 0.001) than the placebo group. No difference was found regarding hemoglobin levels, heart rate, mean arterial pressure, total blood loss, or adverse events. Conclusions: Preoperative melatonin may reduce postoperative pain in CS patients without side effects. This research offers a safe and affordable pain management method for this population, which has clinical consequences. Further research is needed to validate these findings and determine the best melatonin dosage and timing.
