At 42, Caroline, a financial analyst from Manchester, assumed she had left it too late to look into egg freezing.

“The people at the fertility clinic did tell me chances of success weren’t high – under 5% if I remember correctly. So, I was prepared for that,” Caroline, who was single at the time, says. “I wasn’t even 100% sure I wanted children at all at that point, but this was my last and only chance to have children that are biologically related to me, so I went for it anyway.”

Caroline, who is now 50 and married, is one of a number of women who got in touch with the Guardian to share their egg-freezing journey. Experts have cautioned that the procedure is a lottery ticket rather than an “insurance policy” after Jennifer Aniston spoke out about her regret over not having frozen her eggs.

Egg freezing is not normally available on the NHS, though exceptions are made for women having medical treatment that could affect their fertility. Although prohibitively expensive to do privately for many, Caroline could afford it comfortably. She ended up having three separate egg retrievals between the ages of 42 and 43, yielding 13 eggs in total, which were frozen.

“The actual experience was time consuming but fine,” she says, “I never had side-effects from the hormone injections, they were just a bit of a pain.”

At 44 she had another egg retrieval yielding five eggs, the frozen eggs were thawed, and all 18 eggs fertilised with her husband’s sperm at the same time, resulting in three embryos of which one was viable.

“This one viable blastocyst is now a five-year-old boy,” Caroline says. “When I found out my son had come from one of the frozen eggs, rather than one of the fresh ones I retrieved when I was 44, I ruled out attempting to use my own eggs again.”

She is currently 31 weeks pregnant with her second child, with the help of an egg donor. “We were spoiled with success at the first attempt,” Caroline says. “In hindsight, I would have frozen my eggs years earlier, at age 35 perhaps.”

Leto, a data analyst, has done just that. Since undergoing a cycle that extracted 16 eggs two weeks ago, the 35-year-old feels a real sense of relief.

“I did it to stave off my growing anxiety that I would not have the space or lifestyle to afford a child before I was too old to try,” she says. “My usual gloom at my approaching birthday [has] vanished with relief at the thought of the frozen eggs. I feel free from my age.” The process cost £6,000 – Leto says she “lived really frugally” and saved up for 18 months to pay for it, noting that she was “lucky to be able to do that”.

The data analyst views it as a kind of “insurance”. “It’s dislodged this massive, body-shaped ball of anxiety I didn’t realise I was carrying around. It’s a viable sliver of hope, better than getting eggs at age 40,” she says, though she acknowledges that it’s not a guarantee. “I’m aware I’m lulled into a false sense of security, and that there may be another upset in my future where maybe zero are viable,” she says. “It’s scary. I know I’m investing some hope now – to fall from that would be really sad. But what else can I do?”

Sarah, now 49, a self-employed consultant from London, wanted children “very much”, and decided to freeze her eggs at 41 – which she now regrets.

“I had thought I would be too old but was advised it would be no problem and I should get cracking. I spent £15,000 on two rounds of egg freezing, which yielded eight eggs,” she says.

As she was anxious about single parenthood, “because of the stigma”, she waited a couple of years before deciding to proceed on her own.

“My eight eggs resulted in three high-grade embryos, but all three subsequent pregnancies resulted in miscarriage between six and 12 weeks, a highly distressing experience. I did try subsequent rounds of IVF but did not achieve a further pregnancy,” Sarah says. In total, she has spent about £50,000 on IVF treatments and egg freezing.

“I do feel I was misled about being able to buy more time. There are no guarantees, and the process is brutal, especially if it doesn’t result in a baby. I think freezing my eggs was a mistake.”

Bearing in mind the potential difficulties associated with fertility treatment at an older age, finance worker Jessica is relieved she began the process in her 20s. The 28-year-old decided to look into egg freezing last year on the advice of older colleagues, but following tests she was diagnosed with premature ovarian failure. “It’s basically very early menopause – you could become menopausal in your early 30s,” she explains. “It was awful – I didn’t go to work for two days and cried the entire time.”

The finance worker decided to proceed and was advised by doctors to freeze embryos rather than eggs. She used a sperm donor and created six embryos in August 2021, but rather than freezing all of them, she had one transferred immediately. “I asked myself, why am I waiting? My job is only going to get more intense, I’ve always wanted to be a young mum.”

Following two embryo transfers last year, Jessica now has a five-month-old daughter. “It didn’t take me long to conceive but I can’t imagine going through that for years. It’s difficult on your body and psychologically; [during the] two-week wait after the transfer, I was taking pregnancy tests five times a day.”

Her workplace medical insurance paid for about 80% of the total costs due to her diagnosis. “I could financially afford it – that was the biggest thing,” she says, adding: “It’s disgustingly expensive.”

Jessica says undergoing the fertility process was “the best decision of [her] life”. She is hopeful that she may be able to give her daughter a sibling using her frozen embryos. “Because I’m 28 I feel quite confident about having another couple of transfers in the next couple of years and I might have time to have another cycle. If I was older and couldn’t have those options, I would be devastated,” she says. “I feel lucky I’ve caught it so early and can do something about it.”