Embryo Freezing

Embryo freezing is a widely used, effective method to preserve a couple’s chances of having a child at a later time. Survival rates are traditionally higher than that of eggs, and pregnancy rates following frozen embryo transfers are comparable to that of fresh embryo transfers.

Embryos can be frozen at any point after fertilization, usually on Day 3 or 5, depending on the number and quality. Genetic screening (PGS) can be performed to make sure only genetically healthy embryos are frozen.

For those concerned about having a surplus of embryos, they can be frozen at the zygote stage before fusion of the man and woman’s DNA has occurred. This means that technically they are fertilized eggs, not yet embryos.

Once embryos are frozen they can remain viable for several years. When a woman decides to proceed, the embryos are thawed and utilized to establish a pregnancy. Thawed embryos are simply transferred into the uterus.