Motherwort Injection for Preventing Postpartum Hemorrhage in Women with Vaginal Delivery: A Systematic Review and Meta-Analysis of Randomized Evidence

Background. Motherwort injection, a common traditional Chinese medicine, is widely used for the prevention of postpartum hemorrhage (PPH), which has been found to be potential benefit in clinical practice. Objectives. This study aimed to conduct a rigorous systematic review of randomized evidence to offer a comprehensive overview regarding the efficacy and safety of motherwort injection in maternal women with virginal delivery. Methods. We included all randomized controlled trials involving pregnant women in vaginal delivery comparing motherwort injection or combination of motherwort injection and oxytocin with oxytocin alone for preventing postpartum hemorrhage. Paired reviewers independently screened citations, assessed risk of bias, and extracted data. Random-effects model by Mantel-Haenszal method was applied to pool the data. Predefined subgroup analyses and sensitivity analyses were conducted to explore the heterogeneity and robustness of results. The GRADE approach was used to rate the quality of evidence. Main Results. 37 randomized controlled trials involving 7887 participants were included, all of which were at moderate to high risk of bias. Meta-analyses of eight trials showed no significant difference in blood loss and PPH events between oxytocin versus motherwort injection (very low quality). However, pooling of 29 trials suggested a reduced risk of blood loss (within 2 hours: MD -55.06mL, 95% CI -84.06 to -26.06; within 24 hours: MD -85.57 mL, 95% CI -94.26 to -76.88, very low quality), PPH events (RR 0.29, 95% CI 0.21 to 0.39, low quality), and adverse events (Peto OR 0.53, 95% CI 0.40 to 0.70, very low quality) in participants treated with motherwort injection and oxytocin versus oxytocin alone. Conclusions. The current evidence supports the suggestion that the additional use of motherwort injection on oxytocin had a preferable outcome. However, given that the evidence is not definitive with low quality, further careful designed and conducted randomized controlled trials in larger population are warranted to conform the effects.