Ovarian stimulation protocols based on follicle-stimulating hormone glycosylation pattern: impact on oocyte quality and clinical outcome

Objective: To evaluate the impact of follicle-stimulating hormone (FSH) with different glycosylation patterns on oocyte quality and clinical outcomes in an in vitro fertilization (IVF) treatment program.

Design: Prospective randomized, open-label, clinical study.

Setting: Assisted reproduction center.

Patient(s): One hundred eighty-eight infertile couples undergoing assisted fertilization treatment.

Intervention(s): All participants underwent a standard down-regulation with a gonadotropin-releasing hormone (GnRH) analogue. The patients were randomized into three groups: 63 patients received combined sequential acidic and less-acidic FSH, 65 patients received only less-acidic FSH (recombinant FSH), and 60 received only acidic FSH (human-derived FSH).

Main outcome measure(s): Number of mature metaphase II oocytes, embryo quality, clinical pregnancy rates, and implantation rates.

Result(s): The pregnancy and implantation rates were statistically significantly lower in the less-acidic recombinant FSH alone group than in the combined sequential acidic hFSH/less-acidic recombinant FSH, and acidic hFSH alone groups (33.3%, 43.5%, 39% and 17.3%, 24.5%, 20.4%, respectively). Metaphase II oocytes and grade 1 embryos were statistically significantly higher in favor of the combined sequential acidic hFSH/less-acidic recombinant FSH group compared with the less-acidic recombinant FSH alone group.

Conclusion(s): The glycosylation patterns of the two types of FSH implemented for ovarian stimulation have different impacts on oocyte quality and clinical outcome. A sequential combined protocol using both acidic and less-acidic FSH for ovarian stimulation improves oocyte maturity and embryo cleavage, and increases pregnancy and implantation rates.