Follicular diameter and hCG administration do not affect pregnancy rates after clomiphene citrate and intrauterine insemination

Abstract

Objective: Success rates of clomiphene citrate (CC) with timed intrauterine insemination (IUI) in treating infertile couples vary widely in the literature. The heterogeneity of the populations studied as well as differences in the timing of the insemination with regard to follicular size and the preovulatory LH rise and/or the administration of human chorionic gonadotropin (hCG) may contribute to this variance. The intent of this study was to evaluate the pregnancy rates after stimulation with CC/IUI with respect to follicular diameter.Design: Retrospective analysis.Material and Methods: Four hundred ninety-two women who underwent 691 cycles of ovarian stimulation with CC/IUI at the Johns Hopkins Fertility Center between 1/1/98 and 12/30/01 were included in the study. All patients received 50mg/day of CC for 5 days beginning on the 5th day of their menstrual cycle or five days after progesterone-induced withdrawal bleeding. A single IUI was performed in all cases either 24 hours following a spontaneous serum LH surge (>25mIU/ml) or 36 hours after intra-muscular hCG administration (10,000 IU) if the largest follicle had reached a diameter of at least 17mm and the LH was less than 25mIU/ml. For statistical evaluation, t-test, chi square, and correlation analysis were used.Results: There were 223 cycles with a spontaneous LH surge and 468 cycles in which hCG was administered. There were no differences between the two groups in mean age or indication for treatment. The pregnancy rates for the LH surge group (12.4%) and the hCG group (14%) were not statistically different. A spontaneous LH surge was observed at follicular diameters ranging from 12 to 35mm. In the hCG group, the diameter of the leading follicle measured between 17 and 36mm at the time of hCG administration. There was no correlation between follicular diameter and pregnancy outcome in either group. Conclusion: IUI following ovarian stimulation with CC is equally effective 24 hours after a spontaneous LH surge or 36 hours after administration of hCG. Spontaneous LH surges were observed at a variety of follicular sizes with comparable pregnancy rates. Follicular diameter at the time of hCG administration does not appear to have a major impact on pregnancy outcome. Sonographic monitoring of patients treated with CC/IUI did not appear to offer any additional benefit. A urinary LH detection kit may be a more cost-effective way to predict ovulation and time IUI accordingly. Objective: Success rates of clomiphene citrate (CC) with timed intrauterine insemination (IUI) in treating infertile couples vary widely in the literature. The heterogeneity of the populations studied as well as differences in the timing of the insemination with regard to follicular size and the preovulatory LH rise and/or the administration of human chorionic gonadotropin (hCG) may contribute to this variance. The intent of this study was to evaluate the pregnancy rates after stimulation with CC/IUI with respect to follicular diameter. Design: Retrospective analysis. Material and Methods: Four hundred ninety-two women who underwent 691 cycles of ovarian stimulation with CC/IUI at the Johns Hopkins Fertility Center between 1/1/98 and 12/30/01 were included in the study. All patients received 50mg/day of CC for 5 days beginning on the 5th day of their menstrual cycle or five days after progesterone-induced withdrawal bleeding. A single IUI was performed in all cases either 24 hours following a spontaneous serum LH surge (>25mIU/ml) or 36 hours after intra-muscular hCG administration (10,000 IU) if the largest follicle had reached a diameter of at least 17mm and the LH was less than 25mIU/ml. For statistical evaluation, t-test, chi square, and correlation analysis were used. Results: There were 223 cycles with a spontaneous LH surge and 468 cycles in which hCG was administered. There were no differences between the two groups in mean age or indication for treatment. The pregnancy rates for the LH surge group (12.4%) and the hCG group (14%) were not statistically different. A spontaneous LH surge was observed at follicular diameters ranging from 12 to 35mm. In the hCG group, the diameter of the leading follicle measured between 17 and 36mm at the time of hCG administration. There was no correlation between follicular diameter and pregnancy outcome in either group. Conclusion: IUI following ovarian stimulation with CC is equally effective 24 hours after a spontaneous LH surge or 36 hours after administration of hCG. Spontaneous LH surges were observed at a variety of follicular sizes with comparable pregnancy rates. Follicular diameter at the time of hCG administration does not appear to have a major impact on pregnancy outcome. Sonographic monitoring of patients treated with CC/IUI did not appear to offer any additional benefit. A urinary LH detection kit may be a more cost-effective way to predict ovulation and time IUI accordingly.