A systematic review and meta-analysis

Objective: To assess the association of conventional semen parameters and sperm DNA fragmentation with risk of recurrent spontaneous abortion (RSA). Design: Systematic review and meta-analysis. Setting: Not applicable. Patient(s): Total 1,690 male partners of women with RSA, and 1,337 male partners of fertile control women. Intervention(s): Case-control or cohort studies were determined by searching PubMed, Google Scholar, Cochrane Libraries, China Biology Medicine disc, Chinese Scientific Journals Fulltext Database, China National Knowledge Infrastructure, and Wanfang Database. RSAwas defined as two or more previous pregnancy losses. The fertile women refer to the reproductive womenwho have had at least a normal pregnancy history and no history of abortion. MainOutcomeMeasure(s): This study included eight outcome measures: semen volume(ml), semen pH value, sperm density (10/ml), sperm viability (%), sperm progressive motility rate (%), normal spermmorphology rate (%), sperm deformity rate(%), sperm DNA fragmentation index (DFI) (%). The summary measures were reported as standardized mean difference (SMD) with 95% confidence interval (CI). Result(s):Finally, twenty-four studies were included for analysis. Overall, male partners of womenwith RSA had a significantly lower level of sperm density (SMD= -0.53, 95%CI: – 0.75 to –0.30), sperm viability (SMD= -1.03, 95%CI: – 1.52 to –0.54), sperm progressive motility rate (SMD= -0.76, 95%CI:-1.06 – -0.46), and normal sperm morphology rate (SMD= –0.56, 95%CI: – 0.99 to – 0.12), and had a significantly higher rate of sperm deformity rate (SMD=1.29, 95%CI: 0.60 – 1.97), and spermDFI (SMD=1.60, 95% CI: 1.04 to 2.17), when compared with the reference group. However, there were no statistically significant differences for semen volume (SMD= -0.03, 95%CI: -0.14 – 0.08) and semen pH value (SMD= –0.23, 95% CI: –0.50 to 0.05) among 2 groups. Conclusion(s): The results of this analysis support an association of sperm density, sperm viability, sperm progressive motility rate, normal sperm morphology rate, sperm deformity rate, as well as sperm DFI with RSA. However, given the significant heterogeneity between studies and the lack of more detailed data on the subjects, further large-scale prospective studies are needed. Abbreviations: CI = confidence intervals, DFI = DNA fragmentation index, ROS = reactive oxygen species, RSA = recurrent spontaneous abortion, SMD = standardized mean difference. Editor: Burak Bayraktar. This study was supported by the Project Funded by National Natural Science Foundation Program of China (82073653, 81803313 and 81974019), Hunan Provincial Science and Technology Talent Support Project (2020TJ-N07), Natural Science Foundation of Hunan Province (2018JJ2551), Hunan Provincial Key Research and Development Program (2018SK2063 and 2018SK2062), Open Project from NHC Key Laboratory of Birth Defect for Research and Prevention (KF2020006), and China Postdoctoral Science Foundation (2020M682644). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author (JB Qin) had full access to all the data in the study and had final responsibility for the decision to submit for publication. The authors have no conflicts of interest to disclose. All data generated or analyzed during this study are included in this published article [and its supplementary information files]. a Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, b National Health Commission Key Laboratory for Birth Defect Research and Prevention, Changsha, Hunan, c Institute of Cardiovascular Research, Guangdong Provincial People’s Hospital, Guangzhou, Guangdong, China. ∗ Correspondence: Jiabi Qin, Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, 110 Xiangya Road, Changsha, Hunan 410078, China (e-mail: qinjiabi123@163.com). Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc. This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal. How to cite this article: Li J, Luo L, Diao J, Li Y, Zhang S, Chen L, Yang T, Qin J. Male sperm quality and risk of recurrent spontaneous abortion in Chinese couples: a systematic review and meta-analysis. Medicine 2021;100:10(e24828). Received: 4 June 2020 / Received in final form: 16 December 2020 / Accepted: 22 January 2021 http://dx.doi. org/10.1097/MD.0000000000024828