The UK's Family Planning Association (FPA) has launched a new campaign, entitled 'Conceivable?', to warn women over 35 that age alone is not a reliable contraceptive.

The FPA believes media reports about older women's declining fertility may have gone 'too far', misleading women into believing they are no longer fertile after 35. 'Whilst the message about fertility declining with age is an important one, it is often overplayed, alongside disproportionate messaging about unplanned teenage pregnancies', Julie Bentley, chief executive of the charity, told the BBC.

Four per 1000 pregnancies in women aged 40 to 44 now end in abortion, according to the latest 2008 figures from the Office for National Statistics (ONS), a rate comparable to the abortion rate among women under-16. While women between the age of 30 and 34 continue to have the highest birth rate, those over 40 accounted for more than 26,000 live births in 2008. This represents a doubling of the birth rate for that age group since 1988.

Marie Stopes International, the sexual health charity, has welcomed the campaign, stressing the need for women of all ages to have access to medically accurate information and advice. It further emphasised the importance of tests for sexually transmitted infections (STIs), particularly in light of recent data from the Health Protection Agency showing that STIs are increasing among over-45s.

'We welcome the FPA's latest campaign, which importantly highlights that unplanned pregnancies do not just happen to teenagers. Unplanned pregnancy is a risk for any woman of reproductive age,' Emily James said in a press statement on behalf of Marie Stopes International.

A recent study, published in the journal PLoS ONE, showed that women over 30 have only 12 per cent of her original ovarian 'store' of eggs left and that, by age 40, just three per cent of the estimated two million eggs a woman is born with seem to remain. Nonetheless, pregnancies are still possible.