[Pre-ovulatory peaks of gonadotropins. Recent data]

Area of Science:

• Reproductive Endocrinology
• Hormone Biology

Background:

• Ovulation induction often uses human chorionic gonadotropin (hCG), which is non-physiological.
• hCG's effects, including the lack of a Follicle-Stimulating Hormone (FSH) surge and prolonged Luteinizing Hormone (LH) activity, can cause luteal phase defects.

Purpose of the Study:

• To investigate the critical factors in LH peak duration for ovulation induction.
• To explore the potential of recombinant LH (hLH) and the role of specific hormone isoforms.
• To understand the complex mechanisms regulating the preovulatory gonadotropin surge.

Main Methods:

• Analysis of LH peak duration versus amplitude in ovulation induction.
• Evaluation of hCG's physiological impact compared to potential recombinant hLH therapies.
• Characterization of FSH and LH isoforms during the preovulatory peak and their biological activity.

Main Results:

• LH peak duration is more critical for ovulation induction than peak amplitude.
• Non-physiological ovulation induction with hCG may lead to luteal phase abnormalities.
• Recombinant hLH requires specific isoforms with sustained activity (approx. 48 hours) for optimal results, which are still under development.

Conclusions:

• The duration of the LH surge is a critical determinant for successful ovulation induction.
• Developing recombinant gonadotropins with specific isoform profiles is essential for improving fertility treatments.
• The precise interplay of Gonadotropin-Releasing Hormone (GnRH), ovarian steroids, and ovarian peptides in the human preovulatory surge requires further elucidation.