Oocyte Cryopreservation (Egg Freezing)

Egg freezing allows women to preserve mature oocytes before age-related decline in egg quality. The process mirrors IVF stimulation — injectable hormones grow multiple follicles, which are retrieved under sedation. Mature eggs are then vitrified and stored in liquid nitrogen.

When ready to use, eggs are warmed, fertilized with sperm via ICSI, cultured to blastocyst stage, and transferred. Survival rates after vitrification exceed 80–90% in most programs. Success depends heavily on the age at freezing — eggs frozen before 35 have significantly higher live birth potential per egg.

ASRM removed the "experimental" label from egg freezing in 2012. It is widely used for medical fertility preservation (before chemotherapy) and elective fertility preservation.