Interest of Sperm Insemination at 42 Hours Post hCG Compared to 36h in Intrauterine Insemination

Infertility is a major problem affecting approximately 15% of couples worldwide, with a notable increase due to various factors such as advanced maternal age and unhealthy lifestyles. Intrauterine insemination (IUI) is a common treatment option that aims to increase the chances of conception. It is preceded by ovarian stimulation to promote the growth of the follicles. Traditionally, IUI is performed 36 hours after an hCG injection to trigger ovulation, but research suggests benefits to delaying it. Studies have shown that delaying IUI to 42 hours post-hCG could improve oocyte quality and sperm synchronization for fertilization. Randomized clinical trials have shown higher pregnancy rates with delayed UTIs to 42 hours. We therefore propose a superiority study to compare IU at 36 hours and 42 hours post-hCG, taking into account the origin of the sperm used. This study will be the first to evaluate the effect of hCG-IU delay on live birth rates. In all centers, inseminations will be carried out according to the usual procedure. Patients in the experimental group will be stimulated by gonadotropins, ovulation will be blocked by a GnRH antagonist then triggered by hCG allowing IU to occur between 42 and 43 hours post hCG. These treatments are similar to the control group. Only the timing of the IUI compared to the timing of ovulation triggering is different. In the comparison group, ovulation will be triggered in order to carry out intrauterine insemination between 36 and 37 hours post hCG (as is already the case in clinical practice). Blinding is not possible for this study. On the other hand, the different endpoints will be evaluated without the randomization group being blinded by the evaluating gynaecologists. The monitoring of included patients is similar to the care pathway. The follow-up data (pregnancy test, pregnancy ultrasound, progress of the birth) will be carried out in the same way as the care (for which these data are necessarily collected)