RESUMO
OBJECTIVE: Intrauterine insemination (IUI) is a commonly used treatment for infertility. Optimal timing of insemination is achieved either by ultrasound monitoring of follicular growth followed by the administration of human chorionic gonadotropin (hCG) or by the detection of a luteinizing hormone (LH) surge through urinary LH testing (uLH). However, in cycles where follicular growth is monitored, there is a possibility of a premature LH rise which may affect the outcome of treatment. The objective of the current study was to determine the frequency of spontaneous LH surges in ultrasound-monitored IUI cycles. METHODS: One hundred IUI cycles were followed for this prospective cohort study. In combination with ultrasound monitoring, uLH testing was performed twice daily. A serum LH test was performed in the case of an inconclusive uLH test result. IUI was performed either on the day after a positive LH test or, if the diameter of the dominant follicle reached 18 mm and the LH test was still negative, 36 hours after ovulation triggering by administration of hCG. RESULTS: Of the 87 analyzed cycles, 19 (21.8%) exhibited a premature LH surge as detected by urine testing. Eleven further cycles had an inconclusive urine result, and in six of these (6.9% of cycles) the result was confirmed positive by serum LH testing, giving a total of 25 cycles (28.7%) experiencing a premature LH surge. CONCLUSION: A considerable proportion of patients undergoing ultrasound-monitored IUI cycle had a spontaneous LH surge before ovulation triggering was scheduled. This could affect pregnancy rates following IUI.
