Clomiphene citrate induced ovulation and intrauterine insemination: effect of timing of human chorionic gonadotropin injection in relation to the spontaneous LH surge on pregnancy rates

Purpose: To determine the optimal time for administration of human chorionic gonadotropin in clomiphene citrate induced intrauterine insemination cycles.Methods: A retrospective analysis of 171 consecutive cycles was performed. An increase in luteinizing hormone level > 100% over the mean of the preceding two days was defined as luteinizing hormone surge. Human chorionic gonadotropin was given in preparation for intrauterine insemination based on the follicle size and estradiol level prior to surge in 85 cycles (Group A), with the spontaneous surge in 64 cycles (Group B) and not given in 22 cycles (Group C) due to high luteinizing hormone levels.Results: The overall pregnancy rate per cycle was 18.1% (31/171), 15.2% (Group A), 20.3% (Group B) and 22.7% (Group C), (p > 0.50).Conclusion: Although there may be physiological reasons to propose that timing the human chorionic gonadotropin to the luteinizing hormone surge will improve the success rate, they were not demonstrated.