Jennifer Aniston revealed this week that she was trying to get pregnant through IVF at a time when tabloids were obsessively speculating about whether she would have children. The actor told Allure magazine she felt relief now that “the ship has sailed”, but that “I would’ve given anything if someone had said to me: ‘Freeze your eggs. Do yourself a favour.’” Aniston has been widely praised for speaking out about a side to IVF that is not often talked about, but experts cautioned against the idea that freezing eggs is an “insurance policy”. “For someone with the profile of Jennifer Aniston to be speaking about this – the openness is really welcome,” said Ippokratis Sarris, the director of King’s Fertility in London, and a spokesperson for the British Fertility Society. “But egg freezing is not a guarantee.” Egg freezing in the UK has increased tenfold in the past decade from just under 230 cycles in 2009, when the technique was used almost exclusively for medical reasons, to almost 2,400 cycles in 2019. The rise is, in part, due to the advent of egg vitrification, a technique that brought success rates roughly in line with those of IVF using fresh eggs. The process involves dehydrating the egg (to avoid damage from ice crystals), placing it in a small tube and immersing it in liquid nitrogen, which cools the egg from 25C to -196C in just a couple of seconds. “In good hands, frozen eggs can be almost as good, if not as good, as fresh eggs,” said Sarris. This means that a woman who freezes eggs at the age of 30 boosts her chances of successful IVF at 40 years. But, according to Dr Zeynep Gurtin, a lecturer in women’s health at UCL, this concept has led to a false narrative that if you freeze your eggs “you’ll be fine”. “A lot of people who freeze their eggs don’t get pregnant,” Gurtin said. First, only a fraction opt to use the eggs down the line – some get pregnant without IVF, others decide not to for a range of reasons. For those who go ahead, HFEA figures show that, as an average across all age groups, just 2% of all thawed eggs ended up as pregnancies and 0.7% resulted in live births in 2018. For each IVF cycle, this gives a 27% chance on average of a birth for those who froze their eggs before the age of 35 and a 13% for those who froze their eggs after this age. The most common age for egg freezing in the UK is 38 years old. A recent analysis by the Nuffield Council on Bioethics found women often felt frustrated at having received insufficient information on success rates, but also reported feeling relief and a sense of empowerment. Egg freezing, Gurtin suggested, should be viewed as “having a lottery ticket rather than having an insurance policy”. “An insurance policy suggests you’ll definitely get a payout,” she said. “You’re just increasing your chances.” As lottery tickets go, it is an expensive one. The average cost of having eggs collected and frozen is £3,350, with additional £500-£1,500 costs for medication and an ongoing expense of £125-£350 a year for storage. And clinics are not always upfront about the full extent of costs. “In many cases, you’re going to spend a third more than the advertised price – and you’re spending that money for something that’s not an immediate benefit to you,” said Gurtin. “It’s a big gamble.” “When people talk about egg freezing revolutionising women’s lives, you have to ask: how many can afford it?” she added. Travelling abroad, where treatments may be cheaper, is an option but can be logistically problematic. “When it comes to repatriating eggs, sperm and embryos, it is possible, but it’s not always that straightforward,” said Sarris. “You need to follow a process, you don’t just send them with DHL.” Previously, women faced an additional conundrum when deciding at what age to freeze eggs, due to a 10-year storage limit, which would require a woman who froze eggs at 30 to use them by the age of 40 years. The law changed in July to extend the period eggs can be stored to 55 years. Prof Geeta Nargund, the medical director of abc IVF and a senior NHS consultant, was one of those who campaigned for this change. “Increasing the length of time for which women can preserve their eggs will enable them to freeze their eggs when they are younger, and when their eggs are of higher quality, and thus the ultimate chance of success is improved.” Gurtin said the reform had been overdue but it also raised the prospect of egg freezing being aggressively marketed to younger women through Instagram adverts or clinics holding prosecco evenings. “In the US we see really young women being advertised egg storage as the perfect gift for college graduation,” she said. “That’s not appropriate.” For individuals, Sarris said, egg freezing was “just another option within the arsenal of fertility choices”. “As a society, we should be supporting women to have children when they want them,” he said. “Demanding policy changes that deliver family-friendly outcomes, not expecting people to have to choose between their career and having children.”