Leading obstetricians have urged caution over so-called social egg freezing.
Women can chose to freeze their eggs for a number of reasons including putting off childbearing until later in life when the quality of a woman’s eggs may have depleted.
The Royal College of Obstetricians and Gynaecologists (RCog) has said that women should be cautious if they want to freeze their eggs for social reasons.
It said that egg freezing does not guarantee future live births and there are storage limits for how long eggs can be kept frozen.
A spokesman said the best time to freeze eggs is in a woman’s early 20s and “certainly under the age of 37 years old”.
It comes after fertility specialists, writing in BJOG: An International Journal Of Obstetrics And Gynaecology, debated whether social egg freezing should be offered to single women approaching their late 30s.
Arguing against, experts from Imperial College London and Chelsea and Westminster Hospital point out that the proportion of frozen eggs which lead to a live birth among women under 36 is 8.2%, among those aged 36 to 39 this dips to 3.3%.
They point out that, of the 1,173 egg freezing cycles that took place in the UK in 2016, only 32% of patients freezing their eggs were aged 35 or below.
They wrote: “The majority of women are taking measures to preserve their fertility too late, as a ‘last-ditch’ effort, instead of a planned and informed choice in their early to mid-30s.
“Egg freezing is indirectly encouraging women to have children at an advanced maternal age, which carries with it significantly increased risk of medical complications in pregnancy.
“This is especially relevant to women freezing their eggs when they are already in their late 30s.”
Experts from Imperial College London and the Centre for Reproductive and Genetic Health, wrote: “Although delaying childbearing to physiological extremes for social reasons is a reproductive gamble, some women have no alternative, e.g. single women approaching the end of their reproductive years.”
They added: “Single women approaching their late 30s, who desire biologically related children in the future, should consider social egg freezing (SEF).
“Not only does it extend the window of opportunity to find a partner but it also retains the possibility of using a sperm donor as a last resort.
“Women should no longer be punished with childlessness for not finding a partner, nor should they feel pressured into a relationship because of their declining ovarian reserve.
“While it does not guarantee against involuntary childlessness, SEF extends the window of opportunity for single women to find a partner and offers them hope where their ‘biological clock’ would otherwise run out of time.”
Commenting on the debate, Adam Balen, professor of reproductive medicine and spokesman for RCog, said: “Success rates for egg freezing have improved significantly in recent years so offer an opportunity for women to freeze their eggs for social reasons if they’re not ready to have children yet.
“However, it must be stressed that egg freezing does not guarantee a baby in the future.
“Women should also be aware that in the UK the storage limit for eggs frozen for social reasons is currently limited to 10 years.
“While women should be supported in their choices, they must be informed about the relatively low success rates, high costs and side effects associated with egg freezing and IVF treatment.”
He added: “Evidence suggests that the best time to freeze eggs is in a woman’s early 20s and certainly under the age of 37 years old.
“Relationships and sex education, particularly for young people, must include information to enable women and their partners to make informed decisions about when to start a family to ensure the healthiest outcomes.”