An editorial by three London-based senior clinicians in the British Medical Journal (BMJ) warns women about 'leaving it too late' to start a family. Susan Bewley, consultant obstetrician at Guy's and St Thomas'; Melanie Davies, consultant obstetrician and gynaecologist at the Elizabeth Garrett Anderson Hospital at University College Hospital and Peter Braude, Head of the Department of Women's Health at Guy's, King's and St Thomas' School of Medicine write that women who delay getting pregnant until after their mid-thirties defy nature and risk heartbreak. 'Women want to 'have it all' but biology is unchanged', they say.
The authors also implicate the availability of new reproductive technologies as a possible component in delaying reproduction, saying 'the availability of in IVF may lull women into infertility while they wait for a suitable partner and concentrate on their careers'. The concerned doctors note that fewer than 30 per cent of all women undergoing a cycle of IVF achieve a live birth, and this number declines to less than ten per cent in women over 40.
The authors suggest that women may 'blame themselves for choices made without being fully aware of the consequences' and describe the increased risks of later pregnancy as contributing to ill health and unhappiness. Poor outcomes of later pregnancies include increased number of miscarriages, ectopic pregnancies, stillbirth, prematurity and increased admissions to neonatal intensive care. Older mothers are also more prone to postnatal depression.
Over the last twenty years, pregnancies in women over 35 have risen markedly and the average age of first pregnancy (rising from 26 years to 29) and mothers generally has risen. The authors report that, 'the most secure age for childbearing remains 20-35'. For men, the risks of delaying childbearing also rise as sperm counts deteriorate gradually every year and children of older fathers also have increased possible health problems.
Clare Brown, Chief Executive of Infertility Network UK, said 'delaying having children until you are in your thirties is a choice many people make but they need to be aware of the added problems when trying to conceive particularly over the age of 35 when a woman's natural fertility declines'. Dr Bewley said, 'surveys of older mothers show half say they delayed because they had not met a suitable partner. Maybe instead of waiting for Mr Right they ought to wait for Mr Good-Enough, if they want children'.
Late motherhood increases care costs both for the NHS and for employers as older mothers tend to be on higher salaries, which increases the cost of maternity leave. Lord Robert Winston said ageing was the commonest cause of infertility and blamed the trend on employers, saying 'women are expected to be equal to men in the workplace but employers don't accommodate their need to start a family'. There are some social and psychological benefits associated with older motherhood but they are slight as compared to the physical risks incurred. Children of older parents tend to do better at school, although this is possibly due to the fact that older parents tend to come from a higher socio-economic bracket.
In a related story, a survey recently conducted by the Australian Institute of Family Studies found that childless women in their 30s are more reluctant to try IVF than almost any other group. The report found that whilst 66 per cent of women in their 20s would be prepared to use the new technology, this figure dropped to only 52 per cent of childless women in their 30s. By contrast, 69 per cent of childless men would be willing to use IVF if they were having trouble conceiving. The report notes that 'many people of child-bearing age are unaware of the importance of the female partner's age in determining the chance of having an IVF baby'.
The survey points out that only 18 per cent of all IVF treatment cycles result in a live birth and this figure declines rapidly with increasing age. Ruth Weston, a senior research fellow at the institute, said: 'we need a public awareness campaign to alert young adults to the pitfalls of postponing having children, and to let them know IVF is unlikely to be a successful fallback option, especially as they approach their 40s'.