New approaches to ovarian stimulation

Area of Science:

• Reproductive Endocrinology
• Infertility Treatments
• Assisted Reproductive Technology

Background:

• Controlled ovarian hyperstimulation (COH) using gonadotrophin-releasing hormone (GnRH) agonists, particularly the long protocol, is now a first-line therapy.
• This approach effectively prevents premature luteinization, thereby enhancing treatment efficacy in assisted reproductive technology (ART).
• Recombinant human follicle-stimulating hormone (FSH) has demonstrated efficacy in COH protocols, with potential advantages due to its high purity.

Purpose of the Study:

• To evaluate the efficacy and safety of GnRH antagonists in COH protocols.
• To explore alternative stimulation protocols, such as the 'Lübeck protocol', for preventing premature luteinizing hormone (LH) surges.
• To investigate the potential of combining milder stimulation regimens with GnRH antagonists for cost-effective and safe ovarian stimulation.

Main Methods:

• Administration of GnRH agonists followed by COH with human gonadotrophins (long protocol).
• Introduction of GnRH antagonists in COH protocols, including daily midcycle injections ('Lübeck protocol').
• Comparison of pregnancy rates between GnRH agonist long protocols and GnRH antagonist protocols.
• Exploration of combined regimens using clomiphene citrate, low-dose human menopausal gonadotrophin (HMG), and GnRH antagonists.

Main Results:

• GnRH antagonists can be successfully integrated into COH protocols, effectively preventing premature LH rises.
• The 'Lübeck protocol' using GnRH antagonists allows for ovarian stimulation to commence within the spontaneous cycle without a flare-up period.
• Pregnancy rates achieved with GnRH antagonists are comparable to those obtained with the GnRH agonist long protocol.
• Combination therapies with GnRH antagonists show promise for achieving cheap, safe, and efficient ovarian stimulation.

Conclusions:

• GnRH antagonists represent a valuable alternative to GnRH agonists in COH, offering comparable efficacy and improved patient experience.
• Milder ovarian stimulation strategies, potentially combining clomiphene citrate and GnRH antagonists, could reduce patient burden and risks.
• The findings support a shift towards more patient-centered and less invasive approaches in assisted reproduction.