Members of the White Ribbon Alliance, which promotes safe motherhood in Burkina Faso, show the problems women face in motherhood

The story of Yeruknesh Mesfin's death starts on the day of her birth, in an Ethiopian village so remote that its name, Goradit, literally means "cut off". At 10 days old, Mesfin was circumcised by a local woman, and by the age of seven, with no education, she was put to work looking after her family's cattle. At 13, she was abducted and raped by a 32-year-old farmer, who married her; soon afterwards, she became pregnant. Without any medical advice during the whole nine months, she went into labour, "clutching her pillow, calling repeatedly for her mother while tears flowed down her cheeks". Her husband called for help, but the complications proved too difficult for the village's traditional birth attendant. In desperation, the men of the village carried Mesfin to the nearest hospital, where both she and her baby died. She was 15.

Mesfin's tale is one of many in Stories of Mothers Lost, a book by the White Ribbon Alliance, a worldwide movement of grassroots organisations concerned with maternal mortality. Member groups were asked to commemorate a woman in their community who had died in pregnancy or childbirth, and responses flooded in. The project was inspired by the horrendous worldwide statistics surrounding maternal mortality: the fact that a woman dies in pregnancy or childbirth each minute, which adds up to a conservative estimate of 536,000 maternal deaths each year - some believe the toll could be as high as 872,000. While one in 8,200 women in the UK dies in pregnancy or childbirth, in the poorest, most conflict-riven countries, including Niger, Afghanistan and Sierra Leone, that figure rises to a stark, inexcusable, one in eight.

These deaths are highly preventable. It is not a question of finding a vaccine or a cure, of brilliant scientists labouring over test tubes. In many cases, it's not even a question of governments having to find huge amounts of cash: it is estimated that 80% of maternal deaths could be prevented at little or no cost. It is a matter of advocacy and will.

This is an issue that has been on the global agenda for two decades now. In 1987, the World Health Organisation, and other groups, launched the Safe Motherhood Initiative to try to reduce the toll of maternal deaths; in 2000, the UN made that same pledge number five in its list of Millennium Development Goals (MDGs), challenging the world's richest nations to cut maternal mortality by 75% between 1990 and 2015. They are not on target. Only two in five women in sub-Saharan Africa have the assistance of a skilled attendant when they give birth, a situation mostly unchanged since the 1990s. And it's fatal shortfalls like these that mean that the maternal mortality ratio, which needs to decline by 5.5% a year to reach that MDG target, is actually decreasing by less than 1% each year.

Those working in the field speak of "three delays" that contribute to the death toll. The first is the delay in seeking care, which may be because a woman has to wait for permission from the decision-maker of her family, because she knows the family could be bankrupted by hospital costs, or doesn't recognise early enough that her pregnancy is running into trouble. For instance, Stories of Mothers Lost includes the story of Sapna, a woman in India, who delivered two children safely at home, but was too scared to seek hospital care when her third pregnancy ran into complications. She died soon after giving birth.

The second delay regards transportation, which may be unaffordable, unavailable, or simply take too long. Brigid McConville, director of the White Ribbon Alliance in the UK, illustrates this with the story of a female doctor she met in northern Tanzania who had encountered a woman at her clinic whose uterus had ruptured. Her baby had died, "but there was still time to save the woman's life," says McConville, "so the doctor kicked the generator into action, gave her an emergency hysterectomy and brought the baby out."

One of the baby's arms was missing. "The other attendants were saying, 'Sister, you did this so fast, you must have cut the arm off, where is it?' But they couldn't find it. So the doctor went to talk to the woman's husband, who was very quiet. It emerged that he had brought his wife to the clinic on the back of his bike - 50km, over rough track - and she had had a prolapse, and the baby's arm had fallen out. As they cycled, this arm kept getting caught in the spokes of the bicycle, and so the man had had to decide what to do. To save his wife's life, he had to cut the baby's arm off."

The third delay is in receiving care - a woman might arrive at a facility, having spent her labour on the back of a truck, only to find that there are no staff, that there is no blood for a transfusion, or that services are at a price she could never afford. Or they will arrive to find a queue around the block. "In Malawi," says McConville, "I visited maternity wards where there would be 100 women in labour in the courtyard, and only two working midwives."

And in these conditions, the women who survive labour are often physically injured - it's estimated that for every woman worldwide who dies in childbirth, 30 become disabled, injured or ill. Many of them suffer obstetric fistula, a hole opening up between their birth passage and either their bladder or rectum, which results in permanent incontinence. Women with the condition are often abandoned by their communities due to their inability to have more children.

Each country's situation is different, but a huge general improvement in health facilities is a clear necessity, so that every mother has ready access to affordable care. There also needs to be a massive increase in the number of skilled doctors and midwives in developing countries. Access to family planning services is key - it's estimated that if contraception was easily available worldwide, the maternal mortality ratio would plummet by 20%, or even 30%. Hand in hand with that last measure goes the availability of safe, legal abortion. The third biggest cause of maternal death is unsafe terminations.

More generally, it needs to be recognised that this is a major women's rights issue. Globally, the movement to address maternal mortality is well under way and is making significant progress. In Tanzania, tens of thousands of women and men marched this year and last. In India there have also been significant marches. McConville would like to see similar demonstrations worldwide, as well as women in the UK sending for White Ribbon film packs, available through the organisation's website, which they can watch with friends, before doing a whip-round. "Write letters to your local paper, your national paper, to the government," she says. Both Sarah and Gordon Brown have spoken on this issue recently, placing it firmly on the political agenda; the Alliance also has events coming up at the South African world economic forum in June, and at the G8 in Japan in July.

This issue is naturally one that affects whole communities. Babies and young children who have lost their mothers in childbirth are up to 10 times more likely to die prematurely than their peers. McConville tells me of a woman she met in a town in Somalia, known "as the Town of Death. I was there with a journalist who wanted to photograph a family eating lunch, and we went from this ravaged street, with lots of young men lying around with Kalashnikovs - I was terrified - into this courtyard, which was a haven of peace. There were five children sitting around, eating out of a bowl in the middle, and their mother was a local nurse, called Nurta. As we talked, she said, 'See that little boy', and she pointed to one of the children, 'I've never told him this, but he's not my son. I was working in the town, a few years ago, during one of the waves of famine, and I found a woman who had died on the street, who had this newborn baby still suckling her breast. I couldn't do anything for her. All I could do was to pick up her baby, and bring him home'."

· To buy a copy of Stories of Mothers Lost (£25), or order a White Ribbon Alliance film pack, visit Whiteribbonalliance.org/