Whoops! Forgot to have a baby in your twenties? Don’t panic yet
It seems those dire warnings about the ‘fertility cliff’ we topple over at age 35 are based on 300-year-old data
In the current issue of The Atlantic, psychology professor Jean Twenge gets to the root of this notion of a ‘fertility cliff at 35’ – specifically, the claim that one in three women between the ages of 35 to 39 will not be pregnant after a year of trying.
She discovered the figure is based on an article published in 2004 in the journal Human Reproduction, but that the original source is French birth records from 1670 to 1830.
That’s right: the statistics behind the panic date back to a time when there was no electricity, no antibiotics and no fertility treatment.
Twenge cites a more recent and much more encouraging study published in Obstetrics & Gynecology in 2004, headed by David Dunson. It found that, with intercourse twice a week, 82 per cent of
35- to 39-year-old women conceive within a year, compared with 86 percent of 27- to 34-year-olds.
Tony Walsh, who is a gynaecologist and the chairman of SIMS Fertility Clinic, describes Twenge’s findings as “interesting”, and says they shouldn’t be dismissed. However, based on his 20 years’ experience working in the field of fertility, he believes age is an issue. “No one working in fertility could agree that age-related infertility is not a real phenomenon. The decline starts from the late 20s, and it can be steadily plotted from there,” he says.
Cathy Allen, a consultant obstetrician and gynaecologist with the Merrion Fertility Clinic and Holles Street, says “alarm is never good when it comes to fertility. There is no one best time to have a baby. Physically, your 20s may be the best time, but psychologically you may not be ready until your 30s”.
At the same time, she says, “it’s important not to underestimate the effect of age on fertility – there is a definite decline in overall fecundity from the mid-30s on”.
It is also worth noting that age does bring other problems: there is an increased risk of miscarriage and of having a baby with chromosomal abnormalities.
Even Twenge, who believes that the panic over the age of 35 is overstated, says it’s best to have your last child by 40.
Twenge writes: “We’ve rearranged our lives, worried endlessly, and forgone countless career opportunities based on a few statistics about women who resided in thatched-roof huts and never saw a light bulb.”
And for many of us, that’s the point. We have worried endlessly, and possibly even rearranged our lives – and in the end, five in six of us would have gone on to conceive naturally anyway.
The message seems to be that while awareness of your declining fertility is good, panic is not.
In an ideal world, looking after a child might involve being in a relationship, having somewhere secure to live, earning enough money to meet the expenses, being established in a career you’ll be able to return to, should you wish.