Slow release intrauterine insemination versus the bolus technique in the treatment of women with cervical mucus hostility.

Thirty-eight infertile women with cervical mucus hostility were divided at random into two groups for intrauterine insemination with prepared husband's semen. Eighteen women started with slow release (treatment A) and 20 with bolus (treatment B) intrauterine insemination in a cross-over study for four alternating cycles. Insemination was timed 30-36 h after a positive luteinizing hormone (LH) surge or injection of 5000 IU of human chorionic gonadotrophin, given at a follicular diameter of 18 mm during ultrasonically monitored, unstimulated cycles. A Grasby auto-syringe driver (type MS16) was used for the slow release intrauterine insemination to deliver 50 x 10(3) motile spermatozoa every minute for 3 h. Bolus intrauterine insemination was performed by deposition of 0.6 ml of prepared semen without changing the count from the swim-up portion of the washed spermatozoa. A total of 13 patients conceived, nine from 60 cycles of treatment A and four from 66 cycles of treatment B (chi-squared = 2.7143, P less than 0.05 using one-tailed statistics).