5 things women may not know about egg freezing: How to prep your body, pregnancy success rate and more

The age limit for elective egg freezing in Singapore was raised from 35 to 37 years on Jul 1 this year. This means that women between 21 and 37 years old can now opt to freeze their eggs to use in the future.

It’s welcome news for women who want to preserve their fertility while they find a life partner or who are not yet sure if children are on the cards. There are also women who do not want to feel forced to sacrifice their careers to become mothers.

“The age limit of 37 instead of 35 years is backed by research showing that the success rates from egg freezing and the following usage of these eggs are relatively stable for women up to and until the age of 37 years old,” said Dr Kelly Loi, an obstetrics and gynaecology specialist at Mount Elizabeth Hospital.

Prior to the Singapore government allowing for elective egg freezing in women, the procedure was allowed only for medical reasons.

But while the upper age limit extension would allow more women to freeze their eggs, there is a drawback. “The chances of success for this procedure will decrease with age,” said Dr Sheila Loh, an obstetrics and gynaecology specialist at Raffles Fertility Centre.

If you’re considering elective egg freezing, here’s what you need to know:

1. WHAT'S THE BEST AGE TO FREEZE YOUR EGGS?

Doctors advise that women freeze their eggs when they’re younger rather than closer to the upper age limit.

Dr Loi explained that if you’re in your 20s through early 30s, you should be relatively fertile and have a good number of healthy eggs. “But as women get older, the egg numbers and egg quality will decline, resulting in lower success rates later when the eggs are thawed for fertilisation,” she said.

For women 35 years and above, the number of eggs collected would be “much less, of lower quality and have a higher chance of being abnormal”, added Dr Loh.

Other factors that can affect egg quality include a woman’s lifestyle, medical conditions like endometriosis, past ovarian surgery, cancer or even sexually transmitted infections.

2. HOW LONG CAN EGGS BE FROZEN FOR?

According to Dr Loh, the Ministry of Health allows women to store their frozen eggs for as long as they wish.

However, “only legally married couples will be allowed to use the woman’s frozen eggs to try for a baby through in-vitro fertilisation (IVF)”, added Dr Loi.

3. IS THERE A “BEST BEFORE” DATE ON FROZEN EGGS?

“Studies have shown that the frozen eggs do not ‘age’ with time and are unlikely to deteriorate significantly over time,” said Dr Loh.

However, she added, there are few studies on the outcome of frozen eggs in prolonged storage of 10 years.

Remember too, that while frozen eggs stay suspended in time from the moment of retrieval, your body will continue to age – and this may have an impact on your pregnancy.

“Older women have higher risks of miscarriage, hypertension and diabetes during pregnancy, as well as intrauterine growth restriction of the foetuses, and potentially complicated deliveries,” explained Dr Loh.  

4. JUST LIKE PREGNANCY, SHOULD YOU PREPARE YOUR BODY FOR EGG FREEZING?

As egg freezing is a vigorous two-week procedure, Drs Loh and Loi both advise women to prepare their bodies in the lead-up to egg retrieval.

“Women should optimise their health to ensure their eggs are in as good a condition as possible at the point of freezing,” said Dr Loi. This includes eating healthily, stopping smoking and minimising alcohol consumption.

Dr Loh added that you should do moderate exercise of at least 150 minutes a week and keep your BMI between 19 and 25. “This helps with ovarian response and contributes to the success of the procedure,” she said.

And as egg freezing can be a stressful and emotional process, women should not neglect their mental wellbeing. “One’s daily life has to be adjusted around doctor appointments and self-administering injections. This coupled with the increase in hormone levels can lead to increased fatigue and can be emotionally challenging for some women,” said Dr Loi.

She recommended that women consider counselling and other support services to help them navigate their emotions. 

When it’s time to use your frozen eggs via IVF, ensuring that your body is in good health and shape is just as important.

Besides a healthy diet and lifestyle, Dr Loi said women who are planning to get pregnant should take folic acid supplements to prevent birth defects such as spina bifida, where the foetus’ spine and spinal cord do not develop properly.

A visit to a gynaecologist for an ultrasound of the pelvis is also recommended. This is to ensure that the womb is in a good state, free from ovarian cysts, uterine fibroids and endometrial polyps that could hinder embryo implantation, Dr Loi explained.

5. WHAT'S THE “REALISTIC” SUCCESS RATE?

American reality star Kourtney Kardashian Barker recently revealed her troubles with egg freezing and IVF on the third season of The Kardashians. The 44-year-old said she had frozen her eggs when she was “38 or 39” but most of them “didn’t survive the thaw”.

She said none of the seven eggs she had made it into an embryo.

“The freezing of eggs isn’t guaranteed. It’s a misunderstanding, people do it thinking it’s a safety net, and it’s not,” Kardashian Barker said on the episode.

Frozen eggs can become non-viable during freezing and thawing, and techniques vary from one fertility centre to another. However, Dr Loh said these are thought to contribute only a small percentage to the reason why eggs don’t survive.   

The age at which the eggs are frozen could also be a reason. Said Dr Loi: “Even with a healthy diet and lifestyle, it is difficult to prevent the decline with time as the main determinant of a woman’s ovarian reserve is age.”

She added: “Women should be aware of the realistic success rates of the procedure resulting in a baby being born.”  

This success rate, she explained, is significantly dependent on the number of eggs retrieved, maternal age and overall health – the younger a woman is when she freezes her eggs, the better her success rate for getting pregnant.

On average, one egg retrieval cycle should ideally result in the collection of 10 to 15 eggs, said Dr Loi. “Around 90 per cent (of these eggs) will survive the freeze-thaw process, 50 to 70 per cent will fertilise successfully with sperm, of which around 40 to 50 per cent will develop into good quality embryos. And around 50 per cent of these good quality embryos will result in a pregnancy.”

Ultimately, “the frozen eggs do not guarantee a baby; they merely represent a chance to conceive in the future,” Dr Loh said.