It is an age when many are starting to enjoy the freedom of having older children – or their childfree choices – and using their spare time to get back to the gym, go on date nights and worry about their pensions. According to the Office for National Statistics (ONS), however, a growing number of women and their partners are choosing to enter the fray of newborn parenting in midlife.

According to a Guardian analysis of the figures, between 2016-18 and 2019-21 there was a 15% rise in the number of women giving birth in England aged over 50. In the 2019-21 period seven women over 60 gave birth, with two of them over 65.

The issue has come to the fore in recent weeks after the TV presenter Victoria Coren Mitchell, 51, and her comedian husband, David Mitchell, 49, welcomed a second child, and the cookbook author Tana Ramsay, 49, wife of the celebrity chef, Gordon, gave birth to their sixth child.

Tana Ramsay wrote on Instagram that it had been “a nerve-wracking nine months but we’ve made it”, adding: “Ramsay family definitely complete.”

While births to women over 50 are still relatively rare – just 0.04% of all live births in England from 2019-21 – the number is growing. There were 824 new mothers over the age of 50 in that period, up from 701 in the three previous years, a 15% rise, according to the ONS figures.

It forms part of a wider trend towards women giving birth later. In 2021 the average age when giving birth in England and Wales rose to almost 31 years old – the oldest since records began in 1938.

This is not the first baby boom in the over-45s in England and Wales – the years after the second world war also saw relatively high levels of births in that age group, despite the average age of motherhood in the late 1920s being 28 or 29. Recent years have topped the postwar period when it comes to the proportion of mothers giving birth in their late 40s.

One reason for this could be that IVF and improved fertility treatments mean births at older ages are becoming more of a possibility. In 2015, a German woman, Annegret Raunigk, garnered headlines around the world when she gave birth to quadruplets at the age of 65.

The average age for IVF patients increased to 36 in 2021, according to the Human Fertilisation and Embryology Authority (HFEA), the IFV regulator. It was the highest age on record. Patients with no partner averaged 38.1 years old, compared with 36 for those with a male partner and 34.8 for patients with a female partner.

While pregnant women over 40 are no longer referred to as “geriatric” within the NHS, there are well-documented higher risks of complications from this age, including hypertension, diabetes, pre-eclampsia and obesity, according to the National Childbirth Trust. Older mothers also have higher chances of complications during childbirth, and there is a higher likelihood of premature birth and chromosomal anomalies in their babies, such as Down’s, Edwards’ and Patau’s syndromes.

However, Clare Murphy, the chief executive of the British Pregnancy Advisory Service (BPAS), said the medical risks had to be looked at alongside the “very real” barriers to starting a family and the benefits of other factors being in place before giving birth.

“It’s always a bit tiresome when people fret that ‘older’ mothers in the news are somehow misleading younger ones into thinking their reproductive window is infinite,” she said. “Our research here underlines that women are well aware of their fertility window, and that the reasons for delay are not ignorance or confidence in IVF to deliver the family they want, but the very real barriers to starting a family today.”

While some risks would be higher, they had to be looked at alongside factors also important for choosing when to have a child, such as finding the right partner, getting a decent job and saving up for maternity leave, Murphy added.

“We are not very good as a society in setting clinical risks and benefits against wider issues and this is particularly the case with how we discuss motherhood, pregnancy and breastfeeding in particular,” she said. “Women are trying to make the best decisions for themselves and their families in the circumstances they find themselves in.”