Egg Freezing - What Happens?

Saturday night and instead of having tapas at some cool restaurant, attending the opera, or dancing at a club, I am in my pajamas reading the latest edition of Fertility and Sterility. Something happened when I hit 40. Since turning 40, reading or watching TV in my pajamas is exactly how I like to spend my Saturday nights.

I just finished reading an interesting report on egg freezing. A Spanish group looked at 1468 women who underwent elective ("social") egg freezing. These are women under the age of 42 who chose to freeze eggs to preserve their fertility. They did not have cancer or some other pressing medical reason to freeze eggs. Instead they were electively freezing eggs as they were aware of their declining fertility but were not in a position to conceive immediately for various reasons, such as:

  • a medical condition that precludes pregnancy now
  • endometriosis that could decrease their future fertility
  • were having their ovaries removed
  • a particular social situation: single, financial planning, career issues (*most common reason)

For these reasons, egg freezing can make a lot of sense; it preserves the possibility of having a child that is genetically related to you. With the advent of fast-freezing (aka vitrification), egg freezing has become more successful and is being performed much more often. Indeed, there are hundreds of thousands of eggs currently frozen around the world. Such reliable, successful, and affordable egg freezing is only a recent development, so just a small number of women have yet returned to use their frozen eggs. In a study in Fertility and Sterility, between 2007 and 2015, 1468 women froze their eggs while just 137 returned to use them. The study examined these returning women and it represents the largest published study of such women.

Most women studied were age 37-39 at the time of egg freezing and if they returned to use their eggs, they did so about two years later. On average they froze 9 eggs. When they returned, most women (58%) were in a relationship and used their partner's sperm to create embryos with the frozen eggs. The single women (42%) who returned used donor sperm. When they were thawed, 85% of the eggs survived. The pregnancy rate was 39% after embryo transfer. The pregnancy rate was higher for women under 35 at the time of egg freezing and for women who had more than 8 eggs frozen.

The article's author wrote "for many single women who are getting older, the biologic clock represents a serious threat that jeopardizes the possibility of having a biologic child. Usually, the thought of 'running out of time' is a source of a great deal of pressure for them...."

This is what I see in my practice, and while egg freezing is not perfect (after all, it does not guarantee a pregnancy in the future), it does help relieve some of the pressure women feel about their reproductive aging. That itself has value. This study highlights the imperfection of egg freezing as the pregnancy rate was not 100%. On the upside, many women did go on to have successful pregnancies when they might not have if they had not frozen their eggs.

Egg freezing requires a thoughtful conversation with your physician and with yourself... and one best had sooner rather than later!