Objective: To analyze the prognostic value of motile sperm count after swim-up in IUI with husband's sperm in a large group of subfertile couples.
Design: Retrospective study.
Setting: University hospital.
Patient(s): Nine hundred two couples undergoing 3,037 treatment cycles.
Intervention(s): Intrauterine insemination with husband's sperm after swim-up was performed after mild ovarian stimulation with clomiphene citrate and hCG under hormonal and ultrasonographic control of follicle development.
Main outcome measure(s): Pregnancy rate (PR) in correlation to motile sperm count after swim-up.
Result(s): A nonlinear increase in PR per treatment cycle was observed with increasing numbers of motile sperm used for IUI. Insemination with < 0.8 x 10(6) motile sperm after swim-up resulted in a PR of < 1% per treatment cycle. When the motile sperm count was above this level, the PR per cycle reached a plateau of 6.9% to 10.2%, with a minor tendency for increase with higher sperm numbers.
Conclusion(s): Strict analysis of motile sperm count after swim-up is a useful prognostic factor for PRs after IUI. There is a good chance for conception if > or = 0.8 x 10(6) motile sperm are available after appropriate selection methods. Intrauterine insemination performed with considerably higher numbers of motile sperm does not lead to a significant increase in PRs.