Impact of waterbirth on post-partum hemorrhage, genital trauma, retained placenta and shoulder dystocia: A systematic review and meta-analysis

Background: There is insufficient high-quality evidence to either support or discourage water birth (WB). Objectives: To examine different maternal complications of WB compared to standard land birth (LB). The pri- mary outcomes were postpartum hemorrhage and genital trauma. The secondary outcome included the risk of retained placenta and shoulder dystocia. Methods: We searched the electronic databases including PubMed, MEDLINE, Embase, Scopus, EBSCO. In addition, we searched in Google Scholar and ClinicalTrials.gov. The pooled results were used to evaluate the association between WB and obstetric outcomes. This systematic review (SR) was reported according to PRISMA statement 2020. Statistical meta-analyses were performed using Cochrane RevMan version 5.4 software (http:// www.cochrane.org). Results: This systematic review included 22 studies (20 observational studies and 2 RCT). The pooled results showed lower risk of major PPH compared to the LB group (OR = 0.76, 95% CI: 0.66–0.89), no significant difference (OR: 0.94, 95% CI: 0.50–1.78) in the incidence of minor PPH (500-1000 mL blood loss) between WB and LB, no significant difference in the rate of third- and fourth-degree lacerations (OR = 0.87, 95% CI: 0.71–1.07) and in the incidence of retained placenta (OR = 1.30, 95% CI: 0.50–3,35), fewer shoulder dystocia for WB (OR = 0.42, 95% CI: 0.35–0.50). However, compared with the LB group, the rate of first-second-degree tears in the WB group increased by 45% (OR = 1.45, 95% CI: 1.16–1.81). Conclusion: We support ACOG guidelines recommendation for further RCT to assess the impact of water im- mersion during delivery on maternal outcomes.