Are we choosing the correct FSH starting dose during controlled ovarian stimulation for intrauterine insemination cycles? Potential application of a nomogram based on woman's age and markers of ovarian reserve

Purpose: To evaluate the potential application of a nomogram based on woman's age and ovarian reserve markers as a tool to optimize the follicle-stimulating hormone (FSH) starting dose in intrauterine insemination (IUI) cycles.

Methods: We conducted a retrospective analysis enrolling 179 infertile women undergoing controlled ovarian stimulation (COS), followed by IUI. Each woman received an FSH starting dose according to clinical decision. After collecting data about COS and IUI procedures, we calculated the FSH starting dose according to the nomogram. The main outcomes measured were women's baseline characteristics, COS, and clinical outcomes.

Results: The FSH starting dose calculated by the nomogram was significantly lower than the one actually prescribed (p < 0.001), in only 14.8% of the cycles nomogram calculated a higher starting dose. When gonadotropin dose was decreased during COS, and similarly in case of hyper-response (more than two follicles ≥ 16 mm retrieved), the FSH starting dose calculated by the nomogram would have been lower in most of the cases (81.8% and 48.8%, respectively). Conversely, when gonadotropin dose was increased during COS and in case of low ovarian response (no follicle ≥ 16 mm retrieved), the FSH starting dose calculated by the nomogram would have been lower in most of the cases (64.7% and 100%, respectively); in these groups median anti-Müllerian hormone (AMH) level was 5.62 ng/mL.

Conclusions: The application of this nomogram in IUI cycles would lead to a more tailored FSH starting dose and improved cost-effectiveness, although in PCOS women, particularly the ones with high AMH, it does not seem adequate.