That nowast quite enough to feed her four young children and her elderly mother, so every few months González caught a bus to Managua, the capital, and slaved for a week washing and ironing clothes. The pay was three times better, about £2.60 a day, and by staying with two aunts she cut her costs. She would return to her hamlet with a little nest-egg in her purse. She bought herself one treat - a pair of red shoes - but she would leave them with her family in Managua, as they were no good on the mountain trails she had to go up to get home.

During a visit to Managua in February she felt unwell and visited a hospital. The news was devastating. She was pregnant - and it was ectopic, meaning the foetus was growing outside the womb and not viable. The longer González remained pregnant, the greater the risk of rupture, haemorrhaging and death.

What González did next was - when you understand what life in Nicaragua is like these days - utterly rational. She walked out of the hospital, past the obstetrics and gynaecological ward, past the clinics and pharmacies lining the avenues, packed her bag, kissed her aunts goodbye, and caught a bus back to her village. She summoned two neighbouring women - traditional healers - and requested that they terminate the pregnancy in her shack. Without anaesthetic or proper instruments it was more akin to mutilation than surgery, but González insisted. The haemhorraging was intense, and the agony can only be imagined. It was in vain. Maria died. "We heard there was a lot of blood, a lot of pain," says Esperanza Zeledon, 52, one of the Managua aunts.

González was not stupid and did not want to die. She knew her chance of surviving the butchery was small. But being a practical woman, she recognised it was her only chance, and took it. The story of why it was her only chance is an unfolding drama of religion, politics and power that has made Nicaragua a crucible in the global battle over abortion rights. This central American country has become the third country in the world, after Chile and El Salvador, to criminalise all abortions. It is a blanket ban. There are no exceptions for rape, incest, or life- or health-threatening pregnancies.

González was told at the hospital that any doctor who terminated her pregnancy would face two to three years in jail and she, for consenting, would face one to two years. "Nicaraguan doctors are now afraid of going to trial or jail and losing their licence," says Leonel Arguello, president of the Nicaraguan Society of General Medicine. "Many are thinking that instead of taking the risk, it is better to let a woman die."

For the Nicaraguan rich, a problematic pregnancy need not be a death sentence. You can fly to Miami or bribe a discreet private clinic in Managua. But in this wretchedly poor country most young women do not have money. Their choice is to go through with a pregnancy that may kill them, or attempt a DIY termination that may kill them.

As a result of the blanket ban enacted last November at least 82 women have died, according to advocacy groups. "This new law intentionally denies women access to health services essential to saving their lives, and is thus inconsistent with Nicaragua's obligations under international human rights law," says Human Rights Watch.

Nicaragua is famous for its misfortunes: the Somoza dictatorship, the civil war, the impoverishment, the natural disasters. Pro-choice groups say article 143 of the new penal code should be added to that list since it bucks the international trend towards greater abortion access and drags women back to the dark ages.

The anti-abortion camp, in contrast, is euphoric. The new law, it says, is a beacon in the fight to protect the unborn. It is time to celebrate. "Now it is all penalised. And Catholics agree that is should be this way," says Roberto González, 50, a Franciscan priest in Managua. "The population sees the church as behind the law - behind the pressure that succeeded in getting the government to change the law."

Abortion has long been illegal in Nicaragua but there had been exceptions for "therapeutic" reasons if three doctors agreed there was a risk to the woman's life. Those exceptions were no longer necessary, said the Nicaraguan Pro-Life Association, because medical advances obviated the need to terminate pregnancies. "The conditions that justified therapeutic abortion now have medical solutions," says a spokesman. Pope Benedict XVI welcomed the ban but added that women should not suffer or die as a result. "In this regard, it is essential to increase the assistance of the state and of society itself to women who have serious problems during pregnancy."

Nicaragua provides no answer to the debate about when, between conception and birth, life begins. But in the case of González it is clear when it ended: at 28 years. According to Zeledon, the doctors left González with few illusions. "When she came back from the hospital she was very upset. They said they couldn't help her. She knew what this meant: I think she knew she was going to die." Her children have been taken into care and her mother now lives alone. The only mementos of González's visits to her aunts in Managua are some clothes and the red shoes.

No one knows how many other women have died, or are going to die, as a result of the law. The Pope seemed to acknowledge an increased risk to women's health but Nicaragua's government has made no formal study of the law's impact. Women's rights organisations say their 82 documented deaths are the tip of the iceberg. The Pan-American Health Organisation estimates one woman per day suffers from an ectopic pregnancy, and that every two days a woman suffers a miscarriage from a molar pregnancy. That adds up to hundreds of obstetric emergencies per year.

Human Rights Watch, in a recent report titled Over Their Dead Bodies, cited one woman who urgently needed medical help, but was left untreated at a public hospital for two days because the foetus was still alive and so a therapeutic abortion would be illegal. Eventually she expelled the foetus on her own. "By then she was already in septic shock and died five days later," said the doctor.

Another woman, named Mariana, said she obtained a clandestine abortion because her pregnancy aggravated a permanent health condition. "I was very afraid. It was very traumatic not to be able to talk about it, because it is a crime. The abortion saved both me and the two children I already have." The report said the potentially most harmful impact was that girls and women were afraid of seeking treatment for pregnancy-related complications, especially haemorrhaging, in case they were accused of having induced an abortion.

Doctors say they have been put in an impossible position. "We face extremely grave ethical conflicts, all because of politics," says Carla Serrato, a gynaecologist from Nicaragua's state-run Alemán Nicaragüense Hospital. Ligia Altamirano Gómez, an obstetrician, says they fear being overruled by the law. "We are pushed toward illegality."

In an attempt to clarify matters, the health ministry issued protocols last December that said doctors should respond to most obstetric emergencies, including ectopic pregnancies and post-abortion care. To terminate an ectopic pregnancy is legal, it turns out, because since the foetus is not in the womb the procedure would not be an abortion. But such is the climate of fear and confusion that the protocols are widely ignored and misunderstood. The doctors who turned González away from the hospital in Managua thought it was illegal, as did medical staff the Guardian interviewed in Ocotal, González's home town.

"The ban has people frightened. You could lose everything - that's the first thing on your mind," says Dr Arguello, a leading critic of the ban. So far there have been no prosecutions but many doctors are unwilling to take the risk on behalf of women who are often poor, uneducated and from a lower social class.

It is a grim irony that this is happening under a Sandinista government - a movement whose ranks once included advocates for feminism and abortion rights. That was in the 1980s, when the Sandinistas were secular marxists, wore combat fatigues and fought a bloody civil war against US-backed Contra rebels. Things changed. The war ended and the Sandinista leader, Daniel Ortega, lost the presidency in a 1990 election. Church and state were supposedly separate but clerics wielded political clout, none more so than Cardinal Miguel Obando y Bravo. His hostility sank Ortega's attempted comebacks in 1996 and 2001 elections.

In the run-up to last November's election, the cardinal spearheaded a campaign for a blanket abortion ban. Ortega, desperate to regain power, mobilised the Sandinistas behind the cardinal's campaign and helped get the ban enacted just days before the poll. The former revolutionary, now reinvented as a devout Catholic, was rewarded with the presidency.

Ortega, who did not respond to interview requests for this article, has stayed pious in power. Last month he whipped Sandinista assembly deputies into voting with rightwing parties 66-3 to uphold the ban. Many former officials are disgusted with a leader and party they no longer recognise. "It's cynical and it's sad, especially when you consider our high rate of sexual violence and very young mothers," says Moisés Arana, a former mayor of Bluefields. "Here there is a lot of religiosity but only a little Christianity."

The Sandinistas may have changed but Nicaragua's revolutionary heritage has left it with some of Central America's most outspoken feminists. That their former comrades-in-arms are the agents of conservative oppression, as they see it, has them breathing fire. "This is wrong, all wrong. And we are going to fight it all the way," says Ana María Pizarro, a doctor and leading activist. Earlier this month feminists interrupted mass in Managua's metropolitan cathedral to protest against the ban.

The legal strategy is to ask the supreme court to declare the law unconstitutional - while fully expecting to lose since it is stacked with government supporters - to clear the way for a campaign involving the UN and international courts of human rights. They expect to get a sympathetic hearing in Europe, not least at an abortion conference in London later this month organised by Marie Stopes. There are likely to be calls for donor countries such as Britain, Spain and Denmark to threaten to cut aid to Nicaragua. So far there has been so sign of that.

The campaign's problem is that at home it is politically outgunned and unpopular. Lobbying for abortion rights, however limited, is a hard sell to a population largely deferential to the pulpit. The taboo is especially strong in rural areas. Edith Morales, an extrovert mother of two in Sahsa on the Miskito coast, is loud and proud when discussing indigenous rights and her impoverished community's needs. But when discussing the termination of an ectopic pregnancy she had 15 years ago, an act that probably saved her life, she lowers her voice, as if it was something shameful. "People here are very conservative," she explains. Asked if she supports the ban on therapeutic abortions, she shakes her head, and murmurs no.

At the other end of the country, in Bluefields, Inspector Martylee Ingram has the same, almost apologetic tone. She is discussing the harrowing case of an 11-year-old girl, Vera, who has been raped and is now 27 weeks pregnant. Asked if Vera should have the baby, she hesitates. The law says yes and her job is to enforce the law. The inspector shakes her head. "But me, as a woman and policewoman, I'd say no. I feel like she shouldn't have it. It's a baby having a baby. She might not survive."

Last month an assembly vote on whether to uphold the law was an emotional and boisterous affair with dozens of girls and women in the public gallery chanting in protest. Separated by just a sheet of glass, the two sides were a study in contrasts. One comprised mostly elderly men in suits, some of whom opened their speeches by saying "I am a Catholic". The other comprised mostly young women in jeans and T-shirts. "Shame, shame, shame on you all," shouted one teenager. "Daniel Ortega is a rapist," shouted another, a reference to allegations the politican raped his stepdaughter. (He was acquitted of all charges.)

Among the police officers keeping an eye on the protesters was a twentysomething woman with a slight bump beneath her blue uniform. She was four months pregnant and anxious, it turned out, because she had been diagnosed with toxoplasmosis, a bacterium that enters the bloodstream during pregnancy and can gravely damage the foetus. She watched the votes stack up in favour of the blanket ban and shook her head, but said nothing.

A crime in one country, a right in another: the different laws on abortion around the world

Women who become pregnant after being raped, or whose lives are endangered by their pregnancy, are banned from having abortions in just three countries around the world: Nicaragua, Chile and El Salvador. These countries refuse to take into account a woman's age or her ability to care for a child and will prosecute any woman who has an abortion.

In 2006, a UN committee report stated that one of the main causes of maternal mortality in Chile was women turning to illegal abortions and asked the government to stop imprisoning women who sought them.

According to the US-based Centre for Reproductive Rights, currently 26% of the world's population live in the 69 countries that ban abortion. However, 34 of these countries, including Ireland and the United Arab Emirates, make exceptions when a mother's life would be at risk, and 32 countries allow their laws to be interpreted to mean abortion is allowed in these circumstances, including Iran.

Countries such as Rwanda and Morocco allow a woman to end her pregnancy if her physical health is threatened, with some of the 34 countries in this category saying the threat could be serious or permanent.

Malaysia and New Zealand, along with 21 other countries, specifically allow abortion to protect a woman's mental health, and this can be interpreted to include the psychological distress suffered by a woman who is raped or the strain of economic circumstances.

Women can cite socio-economic reasons for an abortion in the UK, India and Luxemburg as well as 13 other countries, while in the 56 countries that are home to 39.3% of the population of the world, there are no restrictions on the reasons given to terminate a pregnancy.

Homa Khaleeli

· This article was amended on October 17 2007. In the article above we referred to toxic plasmosis. That should have been toxoplasmosis - the bacterium that enters the bloodstream. This has been corrected.