More than half of women who have had abortions fell pregnant because their contraception failed, a study has suggested.

The British Pregnancy Advisory Service, who run a number of abortion clinics across the UK, has released data showing that just under a quarter (24.1%) of women who had an abortion were using a hormonal method of contraception like the pill or a long acting reversible contraception – like the implant, intra-uterine devices (IUDs) or coil – when they fell pregnant.

When BPAS took into account women using non-hormonal methods of contraception, like condoms and diaphragms, more than half of women (51.2%) were using contraception when they fell pregnant.

More than 14,000 women, who were treated at BPAS clinics, became pregnant despite using the pill or a long-acting contraceptive.

Oral contraceptive pills are the most popular way of protecting against unplanned pregnancy, but long-acting methods - known as Larcs - are catching up.

Contraceptive pills are estimated to be 91% effective while condoms are 82% effective.

But BPAS says unplanned pregnancies can occur if the method is not inserted properly, or if it moves or falls out.

In addition, hormonal contraception, such as the pill or patch, can mask the symptoms of pregnancy because they may cause light or irregular periods.

This also perhaps explains why women were having late-term abortions (past 20 weeks) - they were using a long-term method of contraception so didn't notice or take into consideration their pregnancy symptoms for a lot longer.

BPAS said the findings dispel the myth that women will not end up having abortions if they are using contraception. While failure rates for many contraceptives are extremely low, they can still fail so safe, abortion care is essential.

It's worth remembering that no method of contraception can ever be 100% effective.

Contraception including birth control pill, IUD, ringpinterest
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'When you encourage women to use contraception, you give them the sense that they can control their fertility – but if you do not provide safe abortion services when that contraception fails you are doing them a great disservice,' Ann Furedi, BPAS' chief executive said in a statement. 'Our data shows women cannot control their fertility through contraception alone, even when they are using some of the most effective methods. Family planning is contraception and abortion.'

The Family Planning Association said that while there are 13 methods of contraception available to women in the UK, there are a lot of myths and misconceptions surrounding their use. The most effective methods are both coils (the IUD and IUS) and the implant which are more than 99% effective.

'Although the injection, pill, patch and vaginal ring can be more than 99% effective if used perfectly every time, they can be forgotten or used incorrectly," Natika Halil, the Chief Executive of the FPA said in a statement. 'The way they are typically used means that 6 in 100 injection users and nine in 100 people using the pill, patch or vaginal ring will get pregnant each year, but women may not always be aware of this.

'If you forget your contraception or think it might have failed it's important to know how to access emergency contraception and that it's available for free from GP surgeries, contraception and sexual health clinics.'

For more information on contraception, visit the FPA's website.

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Olivia Blair
Olivia Blair is Talent Editor at Hearst UK, working predominantly across Cosmopolitan, ELLE, Esquire and Harper's Bazaar. Olivia covers all things entertainment and has interviewed the likes of Margot Robbie, Emma Stone, Timothée Chalamet and Cynthia Erivo over the years.