Freeze eggs now, have kids later

The Amsterdam Medical Centre wants to give single women the option to have children later in life by having their eggs frozen now.

As of next year, women with a child wish but no suitable partner will be able to go to the Amsterdam Medical Centre (AMC) and have their eggs frozen. This should enable them to still have children later in life, when they are no longer producing viable oocytes, through in vitro fertilisation (ivf).

It is not a new medical experiment, says AMC professor of reproductive medicine Fulco van der Veen. He has frozen eggs for regular ivf for two years now after he learned the technique from Japanese doctors who have been doing it for about three years, he estimates. So far, the procedure has been offered to cancer patients before they undergo chemo or radiation therapy that could make them sterile.

Freezing sperm and embryo's - conceived through in virto fertilisation - is common practice and has no significant impact on the success of the pregnancy, but freezing oocytes has proved a lot more complicated.

"Mostly because they are the largest cells in the human body," says Van Veen. "Freezing them the traditional, slow way, creates ice crystals that destroy the cell." The solution was found in freezing them in liquid nitrogen, immersed in a kind of antifreeze.

The chance that a defrosted egg can be fertilised to become a baby depends on the quality of the egg more than the procedure, the professor says.

"Everybody knows it is harder to fertilise an older woman's eggs. So you can't wait too long, but you don't want to start too early either. The hormonal stimulation needed to extract the eggs makes it a strenuous and burdensome procedure."

That is why 25-year-olds are not welcome, but 35-year-olds are. "If there is a deep desire to have children that can not be met at that moment."