Adriana Manzanares’s tiny apartment is sparse, its stucco walls unadorned and lightbulbs exposed. But it’s home. The 28-year-old moved into the flat in Guerrero’s capital, Chilpancingo, only a few months ago, after spending the majority of her 20s in prison for killing her child by undergoing an abortion. It’s a charge she denies, claiming she had a miscarriage.

Mexico has some of the strictest abortion laws in the world. In many states abortion is a punishable offence. At least 679 women were reported or sentenced for the crime of abortion between 2009 and 2011, according to Gire, a reproductive rights organisation. Some women, like Manzanares, have been accused of murder after suffering a miscarriage.

In 2007 the Mexico City federal district passed a law making abortion legal and free in public health centres in the first 12 weeks of pregnancy. Since then, more than 100,000 abortions have been carried out in the city, with district health services having a much lower health risk than clandestine procedures.

Mexico City was the first area in the country to decriminalise abortion. The country’s 31 states have varying restrictions on abortion – while all allow it in cases of rape, it is illegal in most other circumstances. Only 13 states allow the procedure if a woman’s life is in danger, according to Gire. As a result, many clandestine abortions take place, and an estimated 36% lead to complications that require medical attention, according to the Guttmacher Institute, a reproductive health research organisation. The percentage is higher (45%) among poorer women who live in rural areas. The institute says about a quarter of women who experience complications do not get the medical treatment they need.

But the 2007 law fuelled controversy across the country. Since 2007 there has been a rash of measures in Mexico City’s outlying states to crack down further on abortion. “The very conservative right in Mexico … were afraid that what happened in Mexico City would be a green light, that every state would do the same as what Mexico City has done,” says Marta Lamas, an anthropology professor and leading feminist.

Since 2008, 16 states have reformed their constitutions to protect life from the point of conception. This summer, two states sought to change their abortion laws – Nuevo Léon wanted to amend its constitution to define personhood from the moment of conception, while in Guerrero, a bill to legalise abortion was debated. The Guerrero law was voted down in a committee session and never brought to the plenary; the Nuevo Léon amendment has failed to gain traction. But the controversy continues.

Raúl Carrillo Hernández, with umbrella, encourages churchgoers at Santiago Apóstol in Zumpango del Río to sign an anti-abortion petition being circulated throughout the region’s Catholic churches. Photograph: Allison Shelley

Both the conservative Catholic anti-abortion lobby and the feminist pro-choice lobby believe they are defending human rights. Raúl Carrillo Hernández, a 23-year-old activist who collected signatures outside his church condemning the proposed bill in Guerrero, says: “I am very saddened by this law. All of us as humans, we have the right to let others be born, because we had the great opportunity to live.” Mexico is 85% Catholic; the second largest population of Catholics in the world. The church has been lobbying legislators and mobilising its congregation.

Lamas says: “Abortion means the autonomy of women, the liberty of women to decide what they want to do in their lives. Having a child is a very important issue, and you really have to dedicate yourself to it.”

Across Latin America and the Caribbean, abortion laws have come under attack over the past 20 years. Of the five countries (excluding the Holy See) that do not permit abortion under any circumstances, four are in the region – El Salvador, Nicaragua, the Dominican Republic and Chile (the fifth is Malta). Nicaragua and the Dominican Republic previously allowed abortion when a woman’s life was at risk.

Manzanares grew up in a small village. What she has experienced has reshaped her life. “My child was born dead,” she says. But her father accused her of murdering the child and she was taken to court. She spoke Tlapaneco, an indigenous language, so she did not understand the accusations made in Spanish, and her defence was not translated.

The damning evidence was a questionable test on the lung of the foetus. When placed in water, if the lung floats the baby is considered to have been born alive; if it sinks it was a stillbirth. “It’s a non-scientific test. They simply can’t criminalise women with it,” says Veronica Cruz, an activist with the women’s rights group Las Libres.

Veronica Cruz, head of pro-choice organization Las Libres, confers with other activists in Chilpancingo. Photograph: Allison Shelley

Manzanares was sentenced to 27 years in jail for manslaughter. The sentence was later shortened to 22 years. But five years into her term she was helped by Cruz, who had been campaigning for women jailed for murder after abortions. It took two and a half years for the case to be dismissed. “We thought, ‘of course – since it’s an indigenous and poor woman, nobody cares’,” Cruz recalls.

The termination of a pregnancy can occur spontaneously in a miscarriage, or can be induced in the procedure called abortion. Because spontaneous and induced abortions often look the same, with bleeding and the expulsion of the products from the uterus, determining the legality after the event can be complicated.

With the crackdown on abortion, many doctors in Mexico have found themselves caught between the ethics of patient confidentiality and the law. Some doctors have turned their patients in to the police when they suspect them of having self-induced. Others look the other way but worry about being caught. “It’s a question of conscience if a doctor decides to report their patient or not,” says María Leonor Moreno Carreto, a gynaecologists at Chilpancingo’s general hospital. She says the legal restrictions conflict with her medical ethics to preserve confidentiality and to provide the best care.

Since Manzanares’s release this year, she has been reunited with her children. She is now building a life in the city, as she does not want to return to her village or her father.

Speaking in the basic Spanish she learned in prison, Manzanares raises her voice to advocate for women’s rights. She was featured in a documentary, and has spoken at conferences and to the press. “It isn’t homicide,” she says. “Women should be able to decide if they can or can’t have a child. Let’s hope that from now on women won’t go to jail any more because of that.”