Want children of your own, but not quite yet? Luckily, women can freeze their eggs for use at a later date. Welcome to the world of social freezing, or egg freezing.
While freezing sperm cells and embryos has long been established as standard, it was not clear until recently whether egg freezing was as effective.
Then, in 2010, the first European working groups were able to show that certain freezing methods can achieve similar pregnancy rates to fresh egg cells.
Initially, freezing eggs (oocyte cryopreservation) was intended mainly for women dealing with the possibility of a loss of fertility as a side effect of upcoming treatment, such as chemotherapy. However, the technique is now used to offer women more flexible life planning.
It means that women who cannot or who do not want to have children at the current time for private or professional reasons can have their eggs frozen and use them at a later time to get pregnant. The term ‘social freezing’ is now commonly used to designate egg freezing for non-medical reasons.
A woman is born with the amount of eggs she will have for her entire life. This reserve of eggs only shrinks over time.
This means that as a woman ages, two problems arise in terms of her fertility:
The older a woman is, the fewer eggs are available for successful ovulation. This reduces the chances of fertilisation.
Age also affects the quality of the eggs. As a rule of thumb, from around age 35, the likelihood of abnormalities, complications in pregnancy and miscarriages increases dramatically. The chances of becoming pregnant are also reduced.
Egg freezing can increase the chances of pregnancy at a later date by retrieving healthy eggs as early as possible, while the woman is still young, and storing them for use later, when the woman is older and therefore less fertile.
The first step in social freezing is egg retrieval. This stage aims to retrieve as many eggs as possible. Typically, the woman will undergo a hormone treatment in order to stimulate the eggs into maturity. This is monitored with regular ultrasound examinations, before the eggs are removed via a quick and typically painless procedure.
Luckily, the woman does not have to worry that her natural egg reserve will be reduced by this egg retrieval as in the natural cycle, a single follicle would fight against other follicles, and the 'losers' would be lost. In this case, the stimulation accesses this otherwise lost monthly egg pool, so actually the woman's total number of 'eligible' eggs increases with social freezing.
The retrieved eggs are then frozen at minus 196°C where they can be safely stored for decades. Of course, the higher the number of eggs, the greater the chances of one of them resulting in a successful pregnancy.
If the wish to have a child is not fulfilled naturally, the couple can use cryopreserved eggs. These are fertilised with the partner's (or a sperm donor's) sperm outside the body (in vitro fertilisation). Subsequently, one to three of the resulting embryos are transferred into the uterus.
As the chances of natural pregnancy start decreasing from the age of 30, it is best to perform egg freezing as early as possible. The most reliable studies at the moment work on the basis of a 40% chance of a subsequent live birth for 10 stored eggs, 60% for 12 eggs and 90% for 20 eggs, if the eggs were retrieved at the optimal stage of life (i.e. when the woman was younger than 30).
Studies show that children conceived from frozen eggs are at a risk level comparable to that of children conceived during normal IVF/ICSI cycles. The hormone treatment required for egg freezing generally entails mild physical stress for women. These days, hyperstimulation rarely occurs thanks to the improved stimulation protocols. Individual consultation is part of the treatment.
The costs of egg freezing are not yet reimbursed by health insurance companies in Germany. However, an increasing number of employers are offering to cover some of the costs for their employees. In addition to the cost of hormone treatment and egg retrieval, fees are also charged for freezing the eggs and the yearly storage. When the frozen eggs are used, the cost of in vitro fertilisation is also added.