Purpose: Several randomized clinical trials (RCTs) investigated the effects of the manual placental removal on hemorrhage or other hemorrhage-related complications compared with the spontaneous placental removal during cesarean section (CS), while the results remained controversial and were inconsistent. The purpose of this meta-analysis was to quantify the pooled effects of the methods of placental removal on hemorrhage during CS.
Patients and Methods: A systematic literature search was conducted using PubMed, EMBASE, Web of Science, and Google Scholar. Heterogeneity was tested by I ² statistics and Q-statistic. The random-effects model or fixed-effects model were used to calculate the pooled effect for the included studies according to heterogeneity. And the term of standardized mean difference (SMD) with 95% confidence intervals (CI) was pooled and estimated the effects across all studies.
Results: A total of nine RCTs were included in this meta-analysis. Compared with spontaneous group, manual placental removal increased the amount of hemorrhage (SMD = 0.53, 95% CI [0.12, 0.94]; Z = 2.54, P = 0.011) and increased the risk of endometritis (OR = 1.84, 95% CI [1.31, 2.58]; Z = 3.52, P < 0.0001). In contrast, there was no significant difference concerning the operating time (SMD = − 0.30, 95% CI [− 0.85, 0.24]; Z = 1.09, P = 0.276), the length of hospital stays (SMD = 0.11, 95% CI [− 0.08, 0.30]; Z = 1.11, P = 0.265), and blood transfusion requirement (OR = 1.36, 95% CI [0.91, 2.04]; Z = 1.52, P = 0.129), respectively.
Conclusion: Comparing with spontaneous placental removal, manual placental removal appeared to be less positive effect during CS. Because of the limitations of this meta-analysis, more high-quality RCTs are needed to confirm our findings.
Keywords: cesarean section, manual placental removal, spontaneous placenta removal, hemorrhage, meta-analysis