Abstract: 【Objective】 To explore the relationship of sperm parameters and pregnancy outcome after intrauterine insemination (IUI) with abstinence period. 【Methods】 1098 cycles of intrauterine insemination were retrospectively analyzed and the semen parameters were recorded for each insemination

including semen volume

sperm concentration and semen of progressive motility (PR%). The patients were divided into 7 groups according to abstinence period. The sperm parameters and the pregnancy rates of every group were compared. Exclusion of women with lesions of uterus

ovary

oviduct and other diseases

740 cycles were analyzed and the pregnancy rates of every group were compared. 【Results】 Semen volume

sperm concentration and semen numbers of PR increased with duration of abstinence and semen of PR% decreased. Pregnancy occurred in 147 cycles

resulting in an overall pregnancy rate per cycle of 13.4%.The pregnancy rate of every group were 29%

15.6%

14.3%

13.7%

11.1%

8.8%

and 9.7%

respectively. Exclusion of women with diseases

pregnancy occurred in 101 cycles

resulting in an overall pregnancy rate per cycle of 13.6%. The respective pregnancy rate of every group were 35%

18.2%

15.2%

15.1%

9.7%

8.1%

and 5.6%. The first one was significantly higher than other groups.【Conclusions】 Though semen volume

sperm concentration and semen numbers of PR increased with duration of abstinence

the highest pregnancy rates were obtained in cases whose abstinence period was shorter.