Received May 27, 2021
Accepted December 29, 2021

Objective: The prognostic of semen characteristics in intracytoplasmic sperm injection (ICSI) outcomes is not clear. Also, there is no evidence-based recommendation for the abstinence period before ICSI. So, we aimed to assess the influence of the abstinence period and semen characteristics on ICSI outcomes. Methods: A total of 1003 fresh ICSI cycles were divided into six groups; group 1 (1-day abstinence), group 2 (2 days abstinence), group 3 (3 days abstinence), group 4 (4 days abstinence), group 5 (5 days abstinence), and group 6 (6-10 days abstinence). Results: We showed that semen volume (P=0.0001) and total sperm count (P=0.005) were increased in the groups with higher abstinence periods. Other semen parameters did not significantly associate with the abstinence period. The percentage of progressively motile sperm was associated with fertilization rate (P=0.007), and the sperm morphology was associated with cleavage-stage embryo rate (P=0.036). No influence of abstinence or semen parameters on rates of pregnancies was observed. Conclusion: The abstinence period before ICSI can influence the semen volume and total sperm count, and possibly fertilization. Although the sperm with the highest quality are selected for ICSI, the percentages of progressively motile and morphologically normal sperm in the ejaculated semen have a predictive value for fertilization and cleavage rates after ICSI, respectively.