Relationship between leukocytospermia, reproductive potential after assisted reproductive technology, and sperm parameters: a systematic review and meta‐analysis of case–control studies

Background The association of leukocytospermia with male fertility is still under debate. Objective To evaluate the impact of leukocytospermia (≥1 × 106 white blood cells/mL of semen, according to the World Health Organization) in men attending a fertility clinic for couple subfertility, on fertility outcomes after assisted reproductive technology (ART) and on semen quality. Materials and Methods A systematic review with meta‐analysis of case–control studies reporting mean ± standard deviation for values of different seminal parameters (sperm concentration, progressive motility, sperm morphology, sperm DNA fragmentation, semen volume, and Ph) and fertilization rate (FR), or the odds ratio (OR) for clinical pregnancy rate (PR) per cycle after ART in leukocytospermic and non‐leukocytospermic patients was performed. A literature search was carried out in MEDLINE and SCOPUS for English‐language studies published till June 2018. Results Twenty‐eight case‐controlled retrospective studies met the inclusion criteria, comparing fertility outcomes after ART or semen parameters in men with or without leukocytospermia. FR and PR after ART were not significantly different in the two groups. Leukocytospermic samples showed a lower sperm concentration (pooled SMD = −0.14; 95% CI: −0.28, −0.01, I2 = 71%, pfor heterogeneity