The impact of sperm morphology evaluated by strict criteria on intrauterine insemination success

Objective: To determine the relationship between IUI success and the level of morphologically normal sperm, evaluated using strict criteria, in the raw semen. Design: Evaluation of semen quality characteristics and pregnancy results for 538 stimulated IUI cycles. Setting: University medical center infertility clinic. Patient(s): Women undergoing IUI with their partner's semen as treatment for infertility (n = 193). Intervention(s): Ovulation induction using clomiphene citrate, hMG, or both; preparation of raw semen using wash and swim-up or Percoll; deposition of prepared semen at the uterine fundus. Main Outcome Measure(s): Pregnancy status after IUI. Percentage morphologically normal sperm in raw semen, evaluated using strict criteria. Sperm concentration and percentage motile sperm in raw and prepared semen. Result(s): Pregnancy rates (PRs) per cycle were not different when the percentage of morphologically normal sperm in raw semen was <5%, 5% to 9%, 10% to 19%, 20% to 29%, and greater than or equal to 30% (6.5% +/- 3.9%, 13.6% +/- 3.2%, 8.8% +/- 2.4%, 7.1% +/- 2.5%, and 9.7% +/- 3.3%, respectively). Pregnancy rates did not differ among age groups, infertility diagnoses, ovarian stimulation protocols, or semen preparation methods. Conclusion(s): The percentage of morphologically normal sperm in the raw semen, as judged by strict criteria, did not affect IUI PR. Intrauterine insemination appears to be a successful treatment modality for male factor infertility, even when the percentage of morphologically normal sperm in raw semen is very low.