The Therapeutic Effects of a Traditional Chinese Medicine Formula Wuzi Yanzong Pill for the Treatment of Oligoasthenozoospermia: A Meta-Analysis of Randomized Controlled Trials

Oligoasthenozoospermia is a crucial factor in male infertility. Wuzi Yanzong (WZYZ) pill is a popular traditional Chinese medicine (TCM) formula which has been used for male infertility treatment for years. However, its effects on semen quality remain controversial. We conducted a preregistered meta-analysis to assess the effect of WZYZ pill for the therapeutic effects on oligoasthenozoospermia. Five randomized controlled trials including 960 participants were selected from databases of domains in North-East Asian regions, PubMed, Embase, and Cochrane Library. WZYZ pill group yielded a greater mean increment on sperm concentration (5 trials: MD 5.99, 95% CI 2.12-9.85, P = 0.002), spermmotility (5 trials: MD4.57, 95% CI 0.47-8.68, P = 0.03), sperm morphology (2 trials: MD -1.93, 95% CI -4.87-1.01, P = 0.20), activity of acrosomal enzyme (2 trials: MD 28.27, 95% CI 12.41-44.14, P < 0.01), volume of semen (2 trials: MD 0.56, 95% CI 0.21-0.91, P = 0.002), and a decrement of sperm DNA fragmentation index (2 trials: MD -3.82, 95% CI -6.45-1.19, P = 0.004). However, qualities of selected studies were generally unsatisfactory, and there was inherent heterogeneity among some of the outcomes. Despite these limitations, the WZYZ pill improved sperm quality by improving several semen parameters and decreasing DNA damage in oligoasthenozoospermia patients.