Life table analysis of intrauterine insemination pregnancy rates

One hundred twenty-eight couples undergoing intrauterine inseminations were retrospectively reviewed. Life table methodology was used to analyze cumulative pregnancy rates and monthly fecundability. Respective 6- and 12-month cumulative pregnancy rates for each diagnostic group receiving intrauterine insemination were: cervical factor, 28.6% and 42.8%; male factor, 16.7% and 16.7%; female immune factor, 66.7% and 100.0%; male immune factor, 37.5% and 68.8%; and empiric treatment, 60.0% and 60.0%. There was no difference in pregnancy rates between sperm processed with a swim-up in Ham's F-10 or a two-gradient Percoll system. Abnormal sperm penetration assay results in patients with male factor did significantly (p = 0.05) lower the pregnancy rate. It is concluded that if no pregnancy has occurred after six cycles of inseminations, further workup or other treatment may be initiated, but additional pregnancies can be achieved from the seventh through the twelfth cycles of intrauterine insemination.