Pregnancy rates unaffected by sperm count in intrauterine insemination: a retrospective cohort study.

Background: The aim of this study was to elucidate the impact of both pre and postprocessing total motile sperm count (TMSC) on pregnancy rates in a subfertile population undergoing intrauterine insemination (IUI).

Methods: Subfertile couples presenting to the Stanford University Fertility Center during a two-year period were retrospectively enrolled. Eligible couples consisted of women with good ovarian reserve, proven tubal patency, normal anatomy and inducible ovulation. Ovulation induction was administered per standard protocols. IUI was performed using only fresh semen; samples were analyzed pre and post-processing. Pregnancy was established using β-HCG assays performed 15-17 days after IUI. Pregnancy rates for subgroups of pre and postprocessing TMSC were compared.

Results: A total of 981 couples underwent 2231 IUI cycles. Overall, the pregnancy rate was 20.2%. Pregnancy rates did not differ and remained rather stable for the pre (P=0.12) and post (P=0.66) processing semen analysis when stratified for TMSC.

Conclusions: In the absence of teratospermia, TMSC does not appear to impact pregnancy rates in subfertile couples undergoing IUI.