The women's minister, Maria Miller, has said she would back a reduction in the abortion time limit from 24 weeks to 20 weeks. She says the time limit should come down "to reflect the way medical science has moved on" in the care of very premature babies, and that she is motivated by the "very practical impact that late-term abortion has on women".

The British Pregnancy Advisory Service (BPAS) carries out the majority of later abortions in this country. Our staff would have been more than happy to explain to the women's minister just what kind of impact restricting access to abortions after 20 weeks would have on the small numbers of women who need them.

For one, it's fairly unsettling that a minister of state appears so misinformed about science. While survival rates for babies born at 24 weeks and beyond have improved, sadly for the parents who deliver much wanted babies before that point, the prospects remain extremely poor. But the science - or lack of - is only part of the picture here. This is about real women's lives.

Around 2% of all abortions in England and Wales last year were carried out past 20 weeks. The numbers are relatively small but each one comes with their own story that always gets lost in the statistics. BPAS carries out the majority of these abortions, our doctors and nurses providing the most compassionate care possible to women who are often in the most unenviable circumstances.

These women rarely tell their stories, which provides a vacuum that gets filled with assumptions about the kind of women they must be. Who would end a pregnancy at that stage? For a period of one month, we asked staff to keep an anonymous record of the women they saw needing these later abortions.

In just a couple of lines, a story unfolds. Girls who had hidden their pregnancies so long they were on the cusp of the time limit: "15-year-old who had sex for the first time to see what it was like. Thought she might be pregnant but "buried her head in the sand hoping it would go away". She started to self-harm: punching herself in the stomach and making herself vomit. Mother took her to GP suspecting bulimia and the pregnancy was detected." But the stories stretch across women of all ages in all sorts of circumstances. "Mother is in a longstanding relationship, and has three children, one with Down's Syndrome. She has known about her pregnancy and felt that abortion was her best option for "some time", but as her child with Down's Syndrome was scheduled for major surgery, she had to "push it to the back of [her] mind" until the surgery was over"... "University student being treated for depression. She thought her weight gain and nausea were side-effects of her medication, and went to GP to request a different prescription. GP diagnosed her pregnancy"... "This mother has two young children. This pregnancy was unplanned but her current partner had persuaded her to continue. She then found out that he was abusing her children."

It's hard to know which of these women Maria Miller would deny, and why she thinks she is better placed to make a moral decision about their predicament than they themselves.

Early access to abortion services is extremely important. Thanks to tests which can detect pregnancies before a woman has even missed a period, women who know they do not want to continue with their pregnancy can now often refer themselves directly into services, with their care paid for by the NHS. The arrival of Early Medical Abortion - the 'abortion pill' - means women are able to end pregnancies at some of the earliest gestations, without surgical intervention and its accompanying risks.

Abortion is a very safe procedure - inevitably safer than ongoing pregnancy and childbirth - but the earlier it can be carried out the lower the risk to women. But no matter how early and swiftly women can access services, there will always be women who need later care. Our women's minister is absolutely entitled to her own personal convictions about abortion - but she should think hard before she sacrifices these women to assuage her own moral qualms.

Follow Clare Murphy on Twitter: www.twitter.com/bpas1968