Frozen Embryo Transfer

Written by Will Baum
Bookmark and Share

Frozen embryo transfer allows women who have undergone in vitro fertilization (IVF) to try another pregnancy years after the first or to donate their frozen embryos to other couples having difficulties conceiving a child. Frozen embryo transfer has its plusses and minuses. This page will attempt to spell them both out in brief.

The Frozen Embryo Transfer Process

Embryos can be frozen up to six days after fertilization. Three to five days is the standard. Usually, only embryos that are growing successfully will withstand the freezing process. Embryos are cooled slowly until they are stored in liquid nitrogen at -1960° Centigrade.

Thawing is also a slow and careful process. Over 30 minutes, the frozen embryo is placed in a series of solutions. Within 40 minutes, the embryo can be ready for implantation. Embryo freezing began in 1984, but didn't become a common procedure till the late 1980s. No one knows with certainty how long an embryo can stay frozen and still remain viable.

Some embryos perish in the freezing process; others succumb to the stress of thawing. Nearly 70 percent make it. Not all of the embryo has to survive to be transferable. If only one cell of an eight-cell embryo is still alive, a normal pregnancy can still result. As with any IVF, twins and other multiple pregnancies are not uncommon. But frozen embryo transfer is simpler and less expensive than starting IVF from scratch. Look for a fertility clinic experienced in IVF to give you a full consultation about frozen embryo transfer if you are considering the procedure.


Bookmark and Share