Revisiting the impact of ejaculatory abstinence on semen quality and intracytoplasmic sperm injection outcomes.

Background Regulatory bodies recommend inconsistent ejaculatory abstinence lengths before semen analysis. The literature exploring the effect of ejaculatory abstinence length on the outcomes of intracytoplasmic sperm injection is scarce. Objective To study the influence of ejaculatory abstinence length on semen quality and intracytoplasmic sperm injection outcomes. Materials and methods This prospective cohort study included 818 patients undergoing conventional semen analysis from October 2015 to October 2016, in a private university-affiliated IVF centre. Generalized linear models adjusted for potential confounders were used to investigate the associations between ejaculatory abstinence length and seminal parameters and intracytoplasmic sperm injection outcomes. Results Increasing ejaculatory abstinence length was positively correlated with semen volume, sperm concentration, total sperm count, total motile sperm count and sperm DNA fragmentation index. Significant inverse correlations were observed between ejaculatory abstinence length and fertilization rate, blastocyst formation rate, implantation rate and pregnancy rate. A discriminant analysis showed a mean ejaculatory abstinence length in the positive pregnancy group of 3.14 +/- 1.64 days and 4.83 +/- 3.66 days in the negative pregnancy group. A cut-off point was established halfway between ejaculatory abstinence length averages, at 4 days. The ejaculatory abstinence <= 4 days group showed significant lower semen volume, sperm concentration, total sperm count and total motile sperm count compared to ejaculatory abstinence > 4 days group. The ejaculatory abstinence <= 4 days group showed significant lower sperm DNA fragmentation index, and higher rates of fertilization, high-quality embryos on day 3, blastocyst development, implantation and pregnancy compared to ejaculatory abstinence > 4 days group. The implantation rate was significantly higher and the pregnancy rate tended to be higher with one day of ejaculatory abstinence, compared to 2-4 days of ejaculatory abstinence. Conclusions Ejaculatory abstinence periods of >4 days have a detrimental effect on sperm DNA and intracytoplasmic sperm injection outcomes. One day of ejaculatory abstinence significantly improves implantation rate and tends to increase pregnancy rate, compared to 2, 3 and 4 days of ejaculatory abstinence.