The late average age at which Dutch women start families not only poses no medical risk to mothers and children but also offers social benefits, epidemiologists said this week in the Dutch Journal of Medicine (Nederlands Tijdschrift voor Geneeskunde 2008;152:1507-12).
In choosing to have their first child at about 29, Dutch women are practising “prudent family planning,” they argue.
The doctor and epidemiologist Luc Bonneux of the Dutch Interdisciplinary Demographic Institute writes that it is wrong to deduce that the rise in the average age at which women have their first child in the Netherlands results from a substantial increase in pregnancies among older women and therefore leads to more medical problems.
Statistics show that since the introduction of the contraceptive pill in 1970, fertility among women older than 40 has seen a “spectacular” fall. But a strong simultaneous reduction in births among younger women has driven up the mean age for having a first child. As a result an increasing proportion of first children are born to mothers aged 25 to 35.
In 2007 the Netherlands Public Health and Healthcare Council published a report called Postponement of Parenthood: A Medical or Social Problem? (www.rvz.net). The report pointed out that the Netherlands was one of the European leaders in “late parenthood,” and suggested that it posed a problem.
A quarter of the Dutch women aged 40 or more who gave birth in 2005 had their first child, it said. It went on to highlight research by a group of gynaecologists that emphasised the serious consequences of postponing pregnancy, such as greater risks of infertility, complications in pregnancy, and mental and physical disabilities (Nederlands Tijdschrift voor Geneeskunde 2007;151:1593-6).
This week, however, Dr Bonneux writes that although the average age at which Dutch women have their first child has risen by five years since 1970 to 29.4, “averages are treacherous.” The main cause is a drop of 33% in the chance of having a first child before the age of 25, yet after 35 the chance increases, but only by 4.7%. The fertility of women older than 40 halved between 1970 and 2004, dropping from 20 to 10 per 1000 women.
The Netherlands, more than many European countries, has seen childbirth concentrated into an increasingly narrow age band (table).
Births to women by age (%)
| <25 | 25-35 | >35 | |
|---|---|---|---|
| Netherlands (1950) | 15 | 61 | 24 |
| Netherlands (2005) | 11 | 73 | 15 |
| United Kingdom | 25 | 60 | 15 |
| European Union | 17 | 67 | 16 |
The authors accept that women who are planning a family should take into account the natural decline in fertility after 35. But equally they argue that “it would not be wise to encourage women to have their babies at a young age, certainly not before the age of 23” because of disadvantages, including an interruption in education, lower incomes, and instability of relationships.
Dr Bonneux said, “Women in the Netherlands are optimising their social necessities with their biological ones. They are not having children very early but also not very late.” The paper concludes that “the future mothers of the Netherlands seem to be planning and deciding wisely,” and Dutch policy on families should support them.
Cite this as: BMJ 2008;337:a773