Comparing Treatments to Optimize Ovarian Stimulation for IVF

Understanding the Medical Terms

The original study published on U.S. National Library of Medicine is titled “Pharmacokinetics and follicular dynamics of corifollitropin alfa versus recombinant FSH during ovarian stimulation for IVF.” Pharmacokinetics is simply described as what the body does to a drug as it moves into, through, and out of the body. Corifollitropin alfa is a medicine used to treat female infertility. As for recombinant follicle stimulating hormone (rFSH), this is used to help induce ovulation in preparation of fertility treatments like IVF.

‍To put it in simpler terms, we’re looking at how the medicine used to treat infertility moves throughout the body versus a treatment used to induce ovulation before undergoing IVF. The authors, Fauser, Alper, Ledger, Schoolcraft, Zandvliet, Mannaerts, Engage Investigators look at the possibility of a single injection of corifollitropin alfa replacing seven daily injections of rFSH. This is possible by using a gonadotrophin-releasing hormone antagonist protocol in ovarian stimulation prior to IVF.

About the Research

How it works

This is a double-blind randomized controlled trial assessed by the pharmacokinetics and pharmacodynamics (ovarian response) of 150μg corifollitropin alfa versus daily doses of 200IU rFSH in 1509 patients. After given the treatments, comparative analyses were performed on serum concentrations of FSH and the number and size of growing follicles. Coincidentally, the rate of follicular development was similar in both treatment groups. By the 8th stimulation day, 33% of patients treated with corifollitropin alfa reached the criterion for human chorionic gonadotrophin (HCG) injection. Before moving forward, note that HCG is a test done to see if a woman is pregnant because HCG is made by the placenta during pregnancy.

The number of follicles was slightly higher after corifollitropin alfa compared with daily rFSH at stimulation day 8 and on the day of HCG injection. While the pharmacokinetics of corifollitropin alfa and rFSH are seemingly different, their pharmacodynamic profiles at the dosages used are similar.

Results & Conclusion

Similar growth rates

The idea of this study was to compare the pharmacokinetics of corifollitropin alfa versus daily rFSH. A total of 1,509 patients were randomized in a double-blind, controlled trial to either a single injection of 150μg corifollitropin alfa or to daily injections of 200IU rFSH for the first 7 days of ovarian stimulation. While serum FSH immunoreactivity levels were higher up to stimulation day 5 for corifollitropin alfa compared with the daily rFSH, but were similar from day 8 onwards. Corifollitropin alfa treatment resulted in a similar growth rate of follicles though a slightly higher number of follicles were recruited compared with daily rFSH.‍

Overall, the researchers concluded that the pharmacokinetics of corifollitropin alfa and rFSH are quite different but their induced effects at the dosages used are similar. As always, consult your doctor before making any decision about medications or treatments to move forward with. This information is meant to empower and inform you about possible infertility treatment methods.