Why a woman's fertility doesn't always fall off a cliff at 35

Fertility expert blasts celebrity mothers in their 40s who ‘mislead’ women that getting pregnant in later life is easy though many have little problem having babies after 35

One of the UK’s top fertility experts has hit out at older celebrity mothers who ‘mislead’ women into thinking having a baby in their 40s is easy.

In March, BBC presenter Christine Lampard, 42, became the latest in a line of famous faces to give birth in their 40s, following the likes of Nicole Kidman, Madonna and Halle Berry. In 2016, singer Janet Jackson announced she was pregnant just a few weeks before her 50th birthday, and gave birth to a healthy boy in January 2017.

But Dr Geeta Nargund, consultant gynaecologist at London’s St George’s Hospital and a fertility pioneer, has urged women not to delay starting a family in order to avoid a raft of age-related complications.

Women considering starting a family should be warned that their fertility will fall dramatically in their mid 30s

Dr Geeta Nargund, consultant gynaecologist at London’s St George’s Hospital and a fertility pioneer, has urged women not to delay starting a family in order to avoid a raft of age-related complications

Speaking to The Mail on Sunday’s Medical Minefield podcast, she says: ‘A woman’s fertility rapidly declines from her mid-30s. It is important young women have this information so they can plan their families with their own eggs.

‘When celebrity mothers say they had a baby in their early 50s or late 40s, they need to spell out if, as is common in older women, they used a donor egg or frozen eggs. Without that, women think it is easy for them to have babies in their mid-40s, and that is not true.’

Dr Nargund’s comments come amid a social-media campaign to scrap ‘offensive’ pregnancy terms which are commonly used by doctors to describe a mother in her least fertile years, such as ‘geriatric mother’ and ‘advanced maternal age’. The initiative, started by the parenting social network Peanut, calls for an entirely new glossary – clinicians should, for example, use ‘reproductive struggles’ instead of saying infertile and refer to ‘family planning’ rather than a biological clock.

When the campaign was launched on Twitter last month, thousands of women pledged their support. Such phrases had made them feel inadequate, anxious or irresponsible for getting pregnant after the age of 25, they wrote. ‘Society has continued to use psychologically harmful terminology about and towards women at a time when they are, arguably, at their most vulnerable,’ said one woman, a doctor.

Others questioned whether there was a link between age and pregnancy problems, at all. Several told of stress-free births in their mid-40s, while others posted a story about a woman in her 70s conceiving naturally. But among the respondents were a handful of medics, arguing that such phrases represented biological fact.

Christine Lampard, pictured, gave birth in March to her first child at the age of 42

And with the average age of first-time mothers in England and Wales now at a record high of 30 – and creeping up year on year – some say that if the trend continues, the NHS could soon be flooded with pregnant women suffering age-related complications – not to mention the thousands who are left heartbroken, having realised they have left it too late to become mothers.

‘It is not the language that is important, but the facts,’ says Dr Nargund, who has seen ‘too many patients’ in their 40s forced to endure the emotional turmoil of fertility treatment.

It is not the first time this issue has sparked fierce debate. In 2015, Dr Nargund was accused of ‘scaremongering’ after writing a letter to the Government in which she demanded fertility education for teenagers and urged women to ‘start trying by the time they are 30’. This would, she suggested, avoid what she referred to as a ‘fertility time-bomb’ that would cripple NHS IVF services.

Prof Nargund said: ‘When celebrity mothers say they had a baby in their early 50s or late 40s, they need to spell out if, as is common in older women, they used a donor egg or frozen eggs. Without that, women think it is easy for them to have babies in their mid-40s, and that is not true’

According to recent studies, there are more fortysomething first-time mothers than ever before in the UK – four times as many as 20 years ago.

So does Dr Nargund have a point? Let’s start with the biology.

Women are born with roughly two million eggs. But, from puberty, both the number and the quality declines over time.

Gradually, immature eggs – those not released during ovulation – die or are reabsorbed into the body. Meanwhile, those that remain diminish in quality, accumulating DNA errors which, when fertilised, can increase the risk of genetic disorders such as Down’s syndrome.

After the age of 30, the rate of decline in both quality and quantity of eggs rapidly speeds up. In a woman’s 20s, there’s a one in three chance of fertilisation per cycle, compared with a one in five chance in their 30s. 

Dr Nick Raine-Fenning, consultant gynaecologist and associate professor of reproductive medicine at the University of Nottingham said the risks of women giving births in their 40s are overstated. He said: ‘The majority of women will have few, if any, complications even into their late 40s’

At 40, this drops to roughly one in 20 per cycle. But how does this play out in real life? Much of the commonly cited statistics about female fertility date back to data from the 1700s on birth rates among church-going parents in France. 

It was seen as uniquely reliable because the study was not skewed by birth control – many modern studies are thought to be complicated by women’s use of contraception throughout their lives, which could impact fertility.

It showed that 30 per cent of women over 35 who’d been trying for more than a year didn’t get pregnant, compared with less than 20 per cent of those in their late 20s and early 30s. The researchers noted that the steepest decline was seen after the age of 35.

But since then, studies have failed to confirm these findings.

In 2004, US researchers studied more than 700 women in seven European countries and found 86 per cent of 27-34-year-olds conceived within a year, compared with 82 per cent of 35-to-39-year-olds. Other studies had similar results.

‘The majority of women will have few, if any, complications even into their late 40s,’ says Dr Nick Raine-Fenning, consultant gynaecologist and associate professor of reproductive medicine at the University of Nottingham. ‘For individual women, there is no line drawn in the sand in terms of age.

‘The studies look at large groups of women and draw conclusions based on averages. But each woman has her own health profile, so it doesn’t mean what we see in the studies will be true for everyone. Age boundaries mostly serve as a useful indicator for doctors, so they know when to do further tests for genetic conditions that we know are more likely as women age.’

Experts say there is good evidence that, as women get older, the risk of pregnancy complications increases. Studies show that women over 40 are four times more likely than those in their early 30s to develop gestational diabetes, and are twice as likely to suffer pregnancy-induced high blood pressure.

Age can sometimes affect the development of the placenta – the temporary organ that provides oxygen and nutrients to the baby in the womb, increasing the risk of abnormal infant growth. This, in turn, can lead to potentially fatal complications for mother and baby.

Emergency caesarean sections are almost twice as likely in women over 40, compared with those younger, partly due to weaker muscles. One pregnant woman in two over the age of 45 miscarries.

However, Dr Raine-Fenning says these statistics do not necessarily present the full picture. ‘Problems such as high blood pressure and pre-diabetes are much more common in older women to start with,’ he says. ‘Pregnancy is a little bit like running on a treadmill for nine months, so naturally the women who are healthier and fit will suffer fewer complications.

‘Generally, a woman who is fit and healthy aged 40 will likely do just as well – if not better – than someone who is half her age but overweight and with high blood pressure.’

Genetic conditions, such as Down’s syndrome and other developmental disorders, are a definite concern in older mothers, due to the chromosomal problems with older eggs. The risk of Down’s syndrome in a baby is roughly one in 1,250 for a 25-year-old expectant mother, and roughly one in 100 for a woman who conceives at 40. This, in part, is where the focus on the age of 35 comes from – albeit wrongly.

In the 1990s, NHS chiefs analysed data and concluded, based on rough calculations, that at age 35 the risk of Down’s syndrome was raised enough to justify performing an invasive test called an amniocentesis, where a sample of amniotic fluid is extracted from the uterus via a cut in the abdomen and checked for genetic abnormalities.

The procedure carries serious risks of miscarriage and is a hefty cost to the health service.

‘This was simply a cost-benefit calculation, based on old research,’ says Dr Raine-Fenning. ‘There is no evidence that shows anything specifically changes at the age of 35, but the assumption that this is the boundary for a risky pregnancy has stuck.’

Another reason doctors may see 35 as the cut-off for children is due to falling IVF success rates.

‘IVF becomes more of a challenge when women get older, as they have fewer eggs,’ says Dr Raine-Fenning. ‘Success rates are relatively stable until women are 35, and then it starts to decline.’

Experts agree the healthiest way to conceive and give birth after 45 is to use a donor egg. ‘The mother may be perfectly fit and healthy, but there’s a serious risk of genetic abnormalities that come from her egg,’ says Dr Raine-Fenning.

And there’s another part of the equation that experts say is all too often ignored: the father’s age.

According to Dr Nargund, in half of her caseload the fertility issue lies with the man’s age, not the woman’s. Despite the Mick Jaggers of the world, who reproduce well into their 70s, a man over 40 takes five times longer to conceive than one in their 20s, regardless of the woman’s age, according to research.

Last year, US scientists at Rutgers University reviewed 40 years of fertility research and concluded that fathers over 45 were associated with an increased risk of premature birth, late stillbirth, low birth weight, newborn seizures and birth defects such as congenital heart disease – all regardless of the mother’s age.

The quality of sperm cells dramatically decreases with age. Not only are they less mobile, but crucially they are prone to mutations in what’s known as morphology – their shape and structure. It is this that is thought to cause genetic abnormalities in offspring.

A 2013 study of more than 5,000 men aged up to 72 found the proportion of normal sperm started to decline at 34, dropping significantly after 40.

Dr Nargund says: ‘Often couples will be told their fertility troubles are “unexplained”, purely because all the attention has been on what might be wrong with the woman. No one thinks to investigate the man.’

One mother told she was high risk because of her ‘advanced maternal age’ is 43-year-old Fay Millar, a mother-of-three from East Sussex, who gave birth to her youngest child, Charlie, in 2019 when she was 41. ‘I had the same tests I had when I was pregnant a decade previously and there was virtually no difference in my results,’ says the cake-business owner.

‘I was perfectly fit and healthy. But midwives put pressure on me to go into hospital to be induced, even though there were no problems and I was clear I wanted a home birth. The only reason they didn’t want me at home was because of my age.’

Faye’s partner, Bart, is 20 years her senior at 63.

‘No one even said, “He’s a bit old to be a dad.” It was me and my age they were concerned about,’ says Faye. ‘I found it irritating the whole way through until I gave birth.’

Despite the concerns, her ‘perfect birth’ was ‘over and done with in three hours’. The result was Charlie, who is now a healthy, happy two-year-old.

‘I know there’s more of a chance that things can go wrong, but I am proof that you can have perfectly successful pregnancies well into your 40s,’ says Fay.

‘I have a friend who gave birth recently at 47, with no problems. Stigmatising someone purely because of their age, is damaging. Particularly when men don’t get the same treatment.’

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