When a woman needs to preserve her eggs or embryos through freezing (cryopreservation), she usually takes hormones to trigger egg maturation. Then the mature eggs are removed from the ovary. You can have them fertilized in the lab before cryopreservation, or have them frozen unfertilized.
In vitro maturation (IVM) shortens the process by retrieving an immature egg then bringing the egg to maturation in the lab. Immature eggs can be matured in 24-48 hours, then frozen as eggs or as embryos after being fertilized.
One of the most important benefits of IVM is that eggs can be harvested quickly, without waiting for a woman’s natural cycle or fertility drugs to develop mature eggs. Women with cancer may need immediate treatment with chemotherapy, radiation therapy, or other treatments that will damage their ovaries. They don’t have time to wait for their eggs to mature inside the ovary, which makes IVM a life-saving option for both the woman and her future child.
Women with polycystic ovary syndrome can benefit from IVM. These women have a high infertility rate because their eggs don’t mature properly. IVM can help preserve and restore their fertility.
There are several other reasons IVM may be preferred:
Pregnancy rates may be lower with IVM eggs, compared to in vitro fertilization with eggs that matured in the ovary. As a result, Dr. Oktay recommends IVM when there’s no time for other options or when there’s a concern about exposure to high levels of estrogen, as occurs with some types of breast cancer.
IVM has the same risks as the conventional procedure that matures the eggs before removing them from the ovaries. These risks aren’t common, but it’s possible that the immature eggs won’t mature in the lab, that the eggs won’t fertilize, or that none of the fertilized eggs (embryos) will grow.