Meng-Chang Yang,1,* Peng Li,1,* Wen-Jie Su,1 Rong Jiang,1 Jia Deng,1 Ru-Rong Wang,2 Chao-Li Huang3 1Department of Anesthesiology, Sichuan Provincial Peopleâs Hospital, University of Electronic Science and Technology of China, Chengdu, Peopleâs Republic of China; 2Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Peopleâs Republic of China; 3Department of Internal Medicine, Eastern Hospital, Sichuan Provincial Peopleâs Hospital, University of Electronic Science and Technology of China, Chengdu, Peopleâs Republic of China*These authors contributed equally to this workCorrespondence: Ru-Rong WangDepartment of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, Peopleâs Republic of ChinaTel +86 18140049936Fax +86 28-87393632Email wangrurong@scu.edu.cnChao-Li HuangDepartment of Internal Medicine, Eastern Hospital, Sichuan Provincial Peopleâs Hospital, University of Electronic Science and Technology of China, No. 585, Damian, Honghe North Road, Longquanyi District, Chengdu, Peopleâs Republic of ChinaTel +86 13350855681Fax +86 28-87775681Email chaoli_huang@126.comPurpose: 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 I2 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 = â 0.30, 95% CI [â 0.85, 0.24]; Z = 1.09, P = 0.276), the length of hospital stays (SMD = 0.11, 95% CI [â 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