Follicular progesterone elevations with ovulation induction for IVF.

Area of Science:

• Reproductive Endocrinology
• In Vitro Fertilization

Background:

• Follicular progesterone elevation is a recognized concern in ovarian stimulation protocols.
• Understanding the sources and impact of progesterone rise is crucial for improving IVF outcomes.

Purpose of the Study:

• To analyze the origins and consequences of elevated follicular progesterone during ovarian stimulation.
• To explore underlying mechanisms and preventive strategies for in vitro fertilization (IVF) pregnancy outcomes.

Main Methods:

• Review of existing literature on ovarian stimulation protocols and progesterone levels.
• Analysis of factors contributing to progesterone elevation in gonadotropin-releasing hormone (GnRH) agonist and antagonist cycles.
• Evaluation of the impact of progesterone levels on endometrial maturation and IVF success.

Main Results:

• Progesterone elevation can occur in early follicular phase (GnRH agonist flare-up, incomplete luteolysis with GnRH antagonists) and late follicular phase (driven by stimulation parameters).
• Progesterone levels >= 1.5 ng/mL are associated with detrimental effects on pregnancy outcomes, primarily through accelerated endometrial maturation.
• Canceling fresh embryo transfer and opting for frozen-thawed embryo transfer in natural cycles is a recommended strategy to mitigate negative effects.

Conclusions:

• Milder stimulation protocols, earlier ovulation triggers in high responders, and single-blastocyst transfer may prevent follicular phase progesterone elevation.
• Long GnRH agonist and both "long" and long GnRH antagonist regimens appear optimal for managing progesterone levels during stimulation.