The correlation of sperm morphology with unexplained recurrent spontaneous abortion: A systematic review and meta-analysis.

// Xiaodan Cao 1 , Yun Cui 1 , Xiaoxia Zhang 1 , Jiangtao Lou 1 , Jun Zhou 1 and Renxiong Wei 1 1 Department of Clinical Laboratory, Ningbo Municipal Hospital of Traditional Chinese Medicine, Ningbo 315000, China Correspondence to: Renxiong Wei, email: nbxiaowei@163.com Keywords: sperm, morphology, recurrent spontaneous abortion, meta-analysis Received: March 06, 2017     Accepted: March 23, 2017     Published: April 19, 2017 ABSTRACT Sperm morphology displays a potential impact on sperm function and may ultimately impact reproductive function. Current studies have investigated the correlation between sperm morphology with unexplained recurrent spontaneous abortion (RSA) but have shown inconsistent results. Hence, we systematically searched MEDLINE, EMBASE, CNKI databases, as well as the Cochrane Library for studies that examined the association between sperm morphology and unexplained RSA. Fifteen studies were identified, including 883 cases and 530 controls. Our meta-analysis results indicated that the percentage of normal sperm morphology from men with RSA partners was significantly lower than those from normal controls(SMD [95% CI]: − 0.60 [−0.81, −0.40]; P<0.00001) and the percentage of sperm morphologic alterations was significantly higher in patients with RSA compared with the control group (SMD [95% CI]: 0.92 [0.42, 1.43]; P=0.0004). The present study suggested that the percentage of normal sperm morphology may indeed decrease in men from RSA group compared with controls. However, there were some limitations in the study such as the differences in stain techniques and classification criteria. Further evidences are needed to better elucidate the relationship between sperm morphology and unexplained RSA.