The association between follicular size on human chorionic gonadotropin day and pregnancy rate in clomiphene citrate treated polycystic ovary syndrome patients

Objective.To examine leading follicle size on human chorionic gonadotropin (hCG) day and pregnancy rate in anovulatory polycystic ovary syndrome (PCOS) patients treated with clomiphene citrate (CC). Design.Retrospective cohort study. Setting.Fertility clinics in women's health centers. Patients.Data on 291 infertile women with PCOS and irregular cycles who underwent 685 CC treatment cycles were used. Only cycles with one or two follicles >14mm were included. hCG was administered once the leading follicle reached the size of 17-24mm. Main outcome measure(s).Pregnancy rates in relation to leading follicle size. Results.Mono/bi-follicular response was observed in 418 cycles. Pregnancy rates were highest (13.618.6) when hCG was administered in the presence of an 18-22mm follicle, lowest with 17mm, 23mm and 24mm (8.8, 8.8 and 5.7, respectively). No differences were observed in pregnancy rates between mono and bi-follicular cycles. Conclusions.In CC treatment, hCG should be administered when follicular size is at the range of 18-22mm.