Luteinized unruptured follicle syndrome: incidence and recurrence rate in infertile women with unexplained infertility undergoing intrauterine insemination

BACKGROUND: The objective of this study was to determine the incidence and recurrence rate of luteinized unruptured follicle (LUF) syndrome in women with unexplained infertility undergoing intrauterine insemination (IUI). METHODS: A total of 167 women with unexplained infertility who underwent 292 cycles of IUI were enrolled in the study. All patients were treated with clomiphene citrate, 50-150 mg/daily from day 5 to 9 of their menstrual cycle. Ultrasound examination to confirm ovulation was performed on the day of IUI (day 0) and every day thereafter for another 3 days (days 1, 2 and 3). A total of 69 women who failed to conceive in the first cycle and 56 women who failed to conceive in the second cycle underwent second and third cycles, respectively. RESULTS: Of the total 167 patients who underwent first cycle, 42 (25%) had LUF. The incidence of LUF was 56.5% in 69 patients who underwent a second cycle of IUI treatment, of whom 33 patients had LUF in the first cycle with recurrence rate of 78.6%. In 56 patients who underwent 3 consecutive cycles, the incidence of LUF was 58.9% and recurrence rate of 90%. No pregnancies were recorded in patients with LUF during the study period. CONCLUSION: The incidence and recurrence rate of LUF are significantly increased in subsequent cycles of IUI. In these patients, other options of infertility treatment might be justified.