An alarming decline in condom use is putting young people’s health at risk, the World Health Organization has warned.

The WHO’s survey of nearly 250,000 15-year-olds in 42 countries and regions across Europe and Canada found that between 2014 and 2022, condom use among sexually active adolescents declined significantly, putting them at significant risk of sexually transmitted infections, unplanned pregnancies and unsafe abortions.

Almost one-third of 15-year-olds reported that they did not use a condom or take the contraceptive pill. Although sexual activity rates remained relatively stable, with 20% of boys and 15% of girls reporting that they had had sex in 2022, the proportion who used a condom when they last had intercourse fell from 70% to 61% among boys and 63% to 57% among girls.

The UK has some of the lowest condom use, with teenagers in Wales and Scotland reporting among the sharpest falls of all the countries surveyed.

Only 37% of girls in Scotland and 40% in Wales said a condom was used the last time they had sex, a steep drop from 2014 when it was 60% and 57% respectively.

The number of boys using protection also fell, with under half in Scotland (47%) and Wales (46%) saying they used a condom in 2022, down from 59% and 69% in 2014. In England it declined slightly, from 62% to 61%.

This compares with France and Spain, where in 2022 more than two-thirds of girls and around three-quarters of boys said they used a condom. In Germany, the figures for boys and girls were just under 60%. The highest rates were in Armenia, Switzerland and Greece, with around three-quarters of adolescents using condoms.

The report calls on governments to ensure access to high-quality sex education and to make it easier for young people to access contraception services.

“While the report’s findings are dismaying, they are not surprising,” said Dr Hans Henri P Kluge, the WHO’s regional director for Europe.

“Age-appropriate comprehensive sexuality education remains neglected in many countries and, where it is available, it has increasingly come under attack in recent years on the false premise that it encourages sexual behaviour, when the truth is that equipping young people with the right knowledge at the right time leads to optimal health outcomes linked to responsible behaviour and choices.

“We are reaping the bitter fruit of these reactionary efforts, with worse to come, unless governments, health authorities, the education sector and other essential stakeholders … take steps to rectify it.”

Lisa Hallgarten, the head of policy and public affairs at the sexual health charity Brook, said that its own data showed “a concerning reliance in the UK on the withdrawal method, which offers no protection against STIs and is extremely unsafe in preventing pregnancy”.

“At a time of soaring STI rates it is more important than ever that we create a culture of condom use,” she said. In addition to good-quality relationship and sex education, she called for “a national public health campaign around safer sex and condoms and proper funding of our sexual health services to ensure that condoms are free and accessible for all who need them”.

Amelia Whitworth, the head of policy, campaigns and research at the children’s charity Plan International UK, said: “This report should be a red flag for Europe’s governments.

“We have seen an alarming rise in anti-rights movements that seek to strip girls and women of their existing rights in law. From removing women’s right to an abortion to limiting what girls are taught about their bodies, hard-won and essential rights are being eroded.

“We must ensure that all children and young people have access to comprehensive sexuality education to learn about their bodies, their sexuality and what healthy relationships look like. Without meaningful action, we risk girls and young women being robbed of their right to choose their own future.”

The president of the Faculty of Sexual and Reproductive Healthcare, Dr Janet Barter, said the report marked a “worrying trend” and that those most at risk of unintended pregnancy were even less likely to use contraception.

She said: “Young people should receive high-quality, evidence-based education on issues across sexual and reproductive health so they can make healthy reproductive choices for themselves and their partners. Anything less than that fails our young people and future generations.”

A government spokesperson said: “We know there is much work to do to make sure everyone has timely access to sexual health services, and we are determined to shift the focus from treatment to prevention and reduce the inequalities that drive poor health.

“The consultation on proposed changes to the statutory guidance on teaching relationships, health and sex education has now closed and the government will carefully consider next steps.”