Hi everyone. Fertility preservation has been in the news recently as more and more companies are extending fertility preservation as a covered health benefit. For women, fertility preservation may be done in two primary ways; oocyte freezing and embryo freezing. Where a woman is in life and what she wants out of the fertility preservation process will help determine which preservation method is best for her needs.
Biologically, women are most fertile between puberty and age 35. Whereas men produce sperm daily, women are born with all of the eggs they will ever have. Age and hormonal changes result in a decline in egg quality, which can make becoming pregnant more difficult. However, getting pregnant after 35 is possible. In fact, by freezing eggs or embryos, women are able to extend their child bearing years well beyond age 35.
The process for both freezing eggs and freezing embryos begins the same way. A woman’s cycle is closely monitored through the use of blood work and ultrasound. Fertility medication is prescribed in order to achieve the desired result of multiple egg production. Once the eggs are mature, they are harvested via microsurgery during an outpatient procedure.
The primary difference between oocyte freezing and embryo freezing is fertilization. For egg freezing, the eggs are reviewed for quality, then are frozen using vitrification. Embryo freezing takes things a step further.
When embryo freezing is used, the eggs are fertilized with sperm. This sperm may be from a woman’s partner or from donor sperm. ICSI is used when necessary to fertilize the harvested eggs. The medical team is then able to monitor the progress of the resulting embryo’s development. This provides the first level of information as to the true health and quality of the embryos. Additionally, genetic testing may be done on embryos to identify potential health issues and to ensure that the healthiest embryo is transferred back into the mother.
Genetic testing cannot be reliably tested on unfertilized eggs. If you are not sure which option you would prefer, you could freeze half the eggs and half the embryos.
A number of issues come into play when determining your fertility preservation method: