Abstract: [Abstract] Objective  To investigate the various factors that affect pregnancy rate following intrauterine insemination (IUI) with husband sperm. Methods  A total of 3 998 IUI cycles were retrospectively evaluated. The correlation between pregnancy rate and following factors were analyzed including female age and duration of infertility. Results  A total of 3 093 infertile couples were treated with 3 998 cycles of IUI. Five hundred and forty-seven cases conceived the clinical pregnancy during the study. The pregnancy rate was 13.7% per cycle. There were significant differences in female age, duration of infertility, IUI cycles, ovulation protocol, progressive sperm quantity, timing of IUI and diameter of the leading follicular. There were no significant differences in different types of infertility, different causes of infertility, tubal patency, endometrial thickness and endometrium type (P > 0.05). Results of non-conditional stepwise regression analysis showed that the increase of female age and number of IUI cycles were risk factors of IUI outcome. Meanwhile, the stimulating protocol (HMG group and Le? trozole group), progressive sperm quantity (5×106-10×106group) and tubal patency were protective factors of IUI outcome. Conclusion  The female age, the number of cycles, ovulation protocol, progressive sperm quantity and tubal patency are of great importance in the pregnancy rate of IUI cycles.

Key words: intrauterine insemination (IUI), clinical pregnancy rate, age