Serum FSH Levels During Controlled Ovarian Stimulation

Follicle-stimulating hormone (FSH) plays a central role in controlled ovarian stimulation (COS) during in vitro fertilization (IVF) cycles. While baseline FSH is commonly used to assess ovarian reserve, the clinical significance of dynamic FSH changes during stimulation remains unclear. Limited evidence suggests that serum FSH levels during COS may reflect ovarian response and could be associated with follicular development and treatment outcomes, yet FSH is not routinely monitored throughout stimulation protocols. This prospective single-center cohort study aims to evaluate the dynamics of serum FSH levels during COS and to examine their association with ovarian response and IVF outcomes. Serum FSH, luteinizing hormone (LH) and estradiol (E2) will be measured at predefined time points during stimulation. Associations between FSH levels and oocyte yield, embryo development, and pregnancy outcomes will be analyzed to better understand the clinical relevance of FSH monitoring during IVF treatment.