Women over the age of 35 have been warned that age alone is not a contraceptive and that they should take precautions when having sex until after the menopause.
The message from the Family Planning Association (FPA) comes after fears that a "constant stream" of information about women's fertility declining as they get older could be encouraging them to abandon contraception and risk an unplanned pregnancy.
Abortion rates for women aged 40 to 44 in England and Wales are the same as under-16s, at four per 1,000 women. While other Office for National Statistics (ONS) figures reveal that women aged between 30 and 34 have the highest fertility rate, at 113.1 per 1,000 women.
Chief Executive of the FPA, Julie Bentley, said: "Whilst the message about fertility declining with age is an important one, it is often overplayed, alongside disproportionate messaging about unplanned teenage pregnancies.
"It sends an inaccurate message to women and society that only the young fall pregnant and is leading older women to believe their fertility has gone long before it actually has."
"We know that women over 35 change partners and these are a forgotten group, as much of the policy drivers are linked to teenagers. This leaves older women marginalised. We had the health of the Nation in 1992 with a mention of teenage sex and then the teenage pregnancy strategy which was great but we cannot ignore the fact that sex does not stop at 25 years for either gender" - Kathy French, Kent