The average age a Dutch woman has her first baby has now risen to 29.8 years, the national statistics office CBS said on Tuesday.

The age at which women become mothers for the first time has been steadily increasing since the 1970s – when the average age was 24 – and Dutch women are now older than most of their European peers. Spain and Italy have the oldest first-time mothers, with an average age of 31, the CBS said.

Gynaecologists told the Volkskrant that the rise in the age of first-time mothers is worrying because of the risks that pregnancy at an older age bring.

In 1991 they launched a campaign urging women not to wait too long, with the slogan ‘a clever girl has her baby on time’.

‘We can see that the warning has not had much effect,’ fertility professor Bart Fauser told the Volkskrant. ‘People keep on delaying parenthood.’

Gynaecologist Sandra Tanahatoe told the paper that couples are naive about the risk of infertility. ‘One in five couples fail to get pregnant within a year,’ she said. ‘If you are in a good position to have children, then don’t delay,’ she said. ‘There is always a reason to wait.’