The Royal College of Obstetricians and Gynaecologists found a lack of universal curriculum in schools meant not all young people were made aware of their reproductive health.
And a new survey of 1,000 16 to 24-year-olds uncovered “worrying” gaps in knowledge around reproduction.
Around 80% of both sexes believe women’s fertility only starts to decline after the age of 35, and a quarter of boys think women’s fertility starts to decline after the age of 40, compared with 16% of girls.
Two-thirds of those surveyed think men’s fertility only starts declining after the age of 40, with a third believing it doesn’t begin declining until after the age of 50.
Yet experts say fertility rates for both sexes actually decline gradually from the late 20s, and can be affected by genetic and environmental factors such as smoking, obesity and nutrition.
The survey was timed to coincide with a fertility summit being held on Friday.
The event will hear from TV presenter Alex Jones, who is making a documentary highlighting the struggles women can face in getting pregnant.
Infertility is heart breaking and I fully support anything that can be done to help educate young people about the facts Alex Jones, TV presenter
She said: “While exploring my own fertility and meeting couples experiencing fertility problems through making the documentary, I’ve been shocked by the amount of myths and misconceptions about fertility that contribute to a lack of awareness among both men and women.
“Infertility is heart breaking and I fully support anything that can be done to help educate young people about the facts to help them decide when, or if, to start a family.”
Around 15% of the population experience fertility problems while a rising proportion of women in the UK, around 20%, have never had a child.
The survey also found:
The vast majority of young people – around 9 in 10 – are aware that women are most fertile under the age of 30
Encouragingly, 80% of girls and 66% of boys are aware that age is the number one factor which affects female fertility
Girls tend to consider that a higher number of factors affect their fertility than boys
Two-thirds of girls are now aware that being overweight or underweight affects fertility
Of those that had, fewer than 1 in 5 recalled getting the info from official sources, such as through sex and relationship education, their GP or a sexual health clinic
Professor Adam Balen, Chair of the British Fertility Society, said: “The findings of this survey confirm our fears that many young people encounter few opportunities to learn about their reproductive health until they try to conceive.
“Our aim is to ensure that the knowledge components of sex and relationship education not only cover how to avoid pregnancies and sexually transmitted infections, but also include information about fertility to help people plan.
“It should be choice not chance – we want to enable young people to make informed choices about pregnancy, whether that choice is to start a family or not.”
Dr Chris Wilkinson, a consultant in sexual and reproductive healthcare, said: “The findings of this survey support the need for young people to be better informed about fertility and reproductive health. We remain concerned that sex and relationship education in schools is not universal.
“We strongly urge governments across the UK to improve the quality of sex and relationship education so young people leave school armed with the necessary facts about not only safe sex, contraception and consent but also fertility and reproductive health.”