Withholding gonadotropins until human chorionic gonadotropin administration.

Area of Science:

• Reproductive Endocrinology
• In Vitro Fertilization (IVF)

Background:

• Ovarian hyperstimulation syndrome (OHSS) is a risk in IVF.
• High estradiol (E₂) levels before follicle maturation can indicate OHSS risk.

Purpose of the Study:

• To evaluate the effectiveness of "coasting" (withholding gonadotropins) in managing high estradiol levels during IVF.
• To explore the mechanisms and protocols associated with coasting.

Main Methods:

• Coasting involves suspending gonadotropin administration when E₂ levels exceed 3000 pg/mL with immature follicles.
• Monitoring E₂ levels to determine hCG trigger administration or cycle cancellation.
• Considering GnRH-agonist (GnRHa) or GnRH-antagonist protocols.

Main Results:

• Coasting aims to reduce smaller follicles, apoptosis, and vascular endothelial growth factor elaboration.
• The coasting period is generally short.
• Coasting may be less frequent in GnRH-antagonist protocols compared to GnRHa protocols.

Conclusions:

• Coasting is a strategy to mitigate OHSS risk and reduce IVF cycle cancellations.
• Further randomized controlled trials are necessary to compare coasting with embryo cryopreservation for OHSS prevention.