Effect of sperm morphology and number on success of intrauterine insemination

ObjectiveTo assess the effects of the number of motile spermatozoa inseminated and percentage of morphologically normal spermatozoa on the success of IUI.DesignA prospective observational study.SettingUniversity 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 × 106 and 24.28% with normal motile sperm >5 × 106. For patients <25 years old, with number of motile spermatozoa >5 × 106, 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 × 106, and the pregnancy rate was very low (0.84%) with number of motile spermatozoa >5 × 106. When the normal sperm morphology was >30% and number of motile spermatozoa inseminated >5 × 106, 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 × 106, or normal sperm morphology is <30%.