Egg Freezing: What is Egg Freezing?

Transcript

The first healthy pregnancy after egg freezing occurred in 1986. Dr. Linda Porcu in Italy initially used slow freezing technology to freeze eggs. Now the survival of the eggs has improved tremendously. By using vitrification or flash freezing, the eggs become in a glass lake state.

The eggs can survive the thaw 90 to 97% of the time. The genetic complement of the eggs highly depends on the woman’s age. In 2014, the American Society of Reproductive Medicine said that elective egg freezing was no longer considered experimental in their facility.

We’ve had healthy pregnancies from eggs frozen 12 years ago, and that has been a testament to the ability of the eggs to last longer than we previously thought. It’s important to understand that the future partner sperm makes a big difference on how that egg will be fertilized as well as how it will become an embryo and grow.

Utilizing the previous technology, we were concerned that the eggs would not survive the thaw past eight years. The challenge we face now is how many eggs should we encourage women to harvest in order to have a healthy pregnancy in the future? The American Society of Reproductive Medicine says the pregnancy rate per egg is 4% to 12%. But we must take into account the future sperm quality, which is unknown at the time of egg freezing. In addition, we see clinically that some patients have fewer eggs and get great egg embryo development, and some women have many eggs and do not have good quality embryos.

Glossary

Embryo – a human offspring between the second to eighth week after fertilization

Flash freezing – freezing something rapidly to prevent the formation of ice crystals

Vitrification – rapid cooling of a liquid where there is no ice crystal formation