br Discussion IUI with controlled
Discussion IUI with controlled ovarian hyperstimulation has been used over the years as a treatment for mild male factor, anovulation, and unexplained infertility. It is less expensive and less invasive than other assisted reproductive techniques. Therefore, these advantages have made the technique an attractive option for infertile couples. Age, indications of IUI, sperm preparation, and insemination methods are several important factors affecting the outcome of controlled ovarian hyperstimulation-IUI. However, the timing of administration of IUI seems to be the most critical factor among them. It should be noted that medical regimens vary between centers and also between clinicians. Hence, the correct timing of insemination to improve pregnancy has been the subject of recent debate. Huang et al compared 210 IUIs performed at 24 hours and 36 hours with different diagnostic and etiological categories including endometriosis, ovulation dysfunction, and unexplained infertility. The patients were divided into three subgroups who received FSH, hMG, and clomiphen citrate (CC)+hMG. Spermiogram parameters were all normal. Additionally, no significant difference in pregnancy outcomes was found between the two groups. Wang et al demonstrated the effects of different timings (24 hours and 36 hours) of IUI after hCG injection in the subgroups of patients who received clomiphene citrate, clomiphene citrate plus gonadotropin, and gonadotropin alone. The pregnancy rates were found to be similar between two groups. Similarly, Osuna et al performed a systematic review of the literature and they concluded that no significant differences were observed when two inseminations per endothelin receptor antagonist were performed, compared with one insemination. They also found great heterogeneity concerning ovarian management and insemination timing. The same group detected an improved pregnancy rate with two inseminations compared with one insemination when clomiphene citrate with or without gonadotropins and 5000 IU of HCG were used. In another study, Ragni et al detected significant increases in pregnancy rates when the IUI procedure was performed during the preovulatory and periovulatory periods, but not the postovulatory period. According to another study, Kucuk suggested that IUI should be withheld until follicular rupture is detected. He also claimed that monitoring of follicular rupture prior to IUI provides a pregnancy rate similar to natural fecundity. In a Cochrane meta-analysis evaluating the effectiveness of different synchronization methods in natural and stimulated cycles for IUI in subfertile couples, the authors concluded that insufficient evidence exists to determine whether there is any difference in safety and effectiveness between different methods of synchronization of ovulation and insemination among subfertile patients. In our study, we compared the clinical pregnancy rates of patients with PCOS and unexplained infertility according to the timing of single IUI procedures. To homogenize the study groups, we excluded other possible causes of infertility. Clinical pregnancy rates per cycle were 22.9% in the PCOS group and 26.9% in the unexplained group. However, IUI procedures performed 24 hours following hCG trigger day were found to be related to better cycle outcomes among patients with unexplained infertility, unlike PCOS patients. This result can be related to the sperm capacitating process within the woman\'s genital tract. Intercourse performed before ovulation has been related to an increase in the fertilization potential and pregnancy establishment. Primarily, the leading defect in pregnancy establishment for patients with unexplained infertility is fertilization defects. This statement explains the importance of IUI procedure timing, and the technique used for this group of patients who regularly menstruate and ovulate preceding the ovulation induction treatment cycle. Spermatozoa and oocytes have only a limited survival time (around 72 hours and 24 hours, respectively); therefore correct timing of insemination is essential. Delaying the IUI procedure in couples with unexplained infertility theoretically decreases the fertilization potential of the inseminated sperm due to the short viability time of the oocyte. Also, in a prospective randomized controlled study, Blockeel et al demonstrated that significantly higher clinical pregnancy rates per IUI cycle were observed in patients undergoing IUI 1 day after the LH rise, when compared with patients undergoing IUI 2 days after the LH rise in natural cycles. This proves the clinical importance of IUI timing on pregnancy rates among subfertile patients. The main problem for PCOS patients is anovulation. Accordingly, for PCOS patients, IUI timing is not as important as for patients with unexplained infertility. We also found a significant relationship between the hCG trigger day of cycle and clinical pregnancy establishment. This result can be a reflection of higher quality of oocytes in the later hCG day trigger cycles than in earlier hCG day trigger cycles. Perhaps clinicians trigger the preovulatory follicles earlier than physiologically needed, which decreases the fertility potential of an originally competent oocyte. In our study, we also found a significant relationship between hCG day endometrial thickness and clinical pregnancy establishment, which is consistent with the previous literature.