Effect of sperm morphology and number on success of intrauterine insemination

Abstract

Objective: To assess the effects of the number of motile spermatozoa inseminated and percentage of morphologically normal spermatozoa on the success of IUI.

Design: A prospective observational study.

Setting: University teaching hospital and private practice setting.

Patient(s): The study comprised 393 couples who underwent 714 IUI cycles.

Intervention(s): All IUI cycles were preceded by ovarian superovulation with clomiphene citrate 50 mg tablets orally twice daily for 5 days starting on the second day of menses and one hMG ampule 75 IU IM daily for 5 days starting day 5 of the cycle. Cycles were monitored by transvaginal ultrasound. The IUI was performed with a catheter 36 +/- 4 hours after hCG injection.

Main outcome measure(s): Clinical pregnancy.

Result(s): A total of 79 clinical pregnancies were obtained, for a pregnancy rate per cycle of 11.06%. The pregnancy rate per cycle was 5.55% when the number of motile spermatozoa was <5 x 10(6) and 24.28% with normal motile sperm >5 x 10(6). For patients <25 years old, with number of motile spermatozoa >5 x 10(6), the pregnancy rate per cycle was 28.2%, which is significantly higher than that of other age groups. Above the age of 35 years, no pregnancies were reported with number of motile spermatozoa <5 x 10(6), and the pregnancy rate was very low (0.84%) with number of motile spermatozoa >5 x 10(6). When the normal sperm morphology was >30% and number of motile spermatozoa inseminated >5 x 10(6), the pregnancy rate was 20.77%.

Conclusion(s): Intrauterine insemination used for treating male factor infertility has little chance of success when the woman is older than 35 years, the number of motile spermatozoa inseminated is <5 x 10(6), or normal sperm morphology is <30%.