Gonadotropin-Releasing Hormone-Agonist Triggering and a Freeze-All Approach: The Final Step in Eliminating Ovarian Hyperstimulation Syndrome?

Importance: In vitro fertilization (IVF) has evolved dramatically in recent decades; however, clinical practices have been slow to adopt these advancements, particularly regarding final oocyte maturation and the timing of embryo transfer. Concerns still exist over the ability of gonadotropin-releasing hormone (GnRH) agonists and elective embryo cryopreservation to reduce the risk of ovarian hyperstimulation syndrome (OHSS) without compromising pregnancy outcomes.

Objective: This review investigates IVF outcomes associated with GnRH-agonist triggering and elective embryo cryopreservation. The safety and efficacy of GnRH-agonist triggering are compared with conventional human chorionic gonadotropin triggering, and frozen embryo transfers are weighed against fresh transfers.

Evidence Acquisition: A literature search was conducted using OVID (MEDLINE) and PubMed databases. The search strategy included keywords such as "ovarian hyperstimulation syndrome or OHSS," "GnRH-agonist triggering," "cryopreservation or freeze-all," and "IVF outcomes." A total of 214 articles were considered for review.

Results: Gonadotropin-releasing hormone agonist triggering reduces OHSS incidence without compromising oocyte retrieval and fertilization rates in donor and autologous cycles. However, GnRH-agonist triggering causes a luteal phase deficiency in autologous cycles, deleteriously compromising pregnancy rates. Elective embryo cryopreservation overcomes this deficiency, reducing the risk of OHSS and may improve neonatal and obstetric outcomes.

Conclusions: Gonadotropin-releasing hormone agonist triggering should be considered in all donor cycles. It should also be selectively considered in autologous cycles in combination with elective cryopreservation of all viable embryos.