RECIFE (Reuters) – Six months pregnant with her first child, Eritania Maria has a rash and a mild fever, symptoms of the Zika virus linked to brain deformities in newborn children in Brazil.

But the 17-year-old is too scared to take a test to confirm if she has Zika.

Like other women in the slums of Recife, which squat on stilts over mosquito-ridden marshland in northeast Brazil, Maria has few options if her child develops microcephaly, the condition marked by an abnormally small head and underdeveloped brain that has been linked to Zika.

Brazil has amongst the toughest abortion laws in the world and is culturally conservative. Even if she wanted an illegal abortion and could afford one, Maria is too heavily pregnant for a doctor to risk it. So she prefers not to know.

“I’m too scared of finding out my baby will be sick,” she told Reuters, her belly poking out from beneath a yellow top.

The Zika outbreak has revived the debate about easing abortion laws but Maria’s case highlights a gap between campaigners and U.N. officials calling for change and Brazil’s poor, who are worst affected by the mosquito-borne virus yet tend to be anti-abortion.

Add a conservative Congress packed with Evangelical Christians staunchly opposed to easing restrictions, plus the difficulty of identifying microcephaly early enough to safely abort, and hopes for change seem likely to be frustrated.

As with many countries in mostly Roman Catholic Latin America, Brazil has outlawed abortion except in cases of rape, when the mother’s life is at risk or the child is too sick to survive.

An estimated 850,000 women in Brazil have illegal abortions every year, many under dangerous conditions. They can face up to 3 years in prison although in practice, jail terms are extremely rare.

With two-thirds of the population Catholic and support for Evangelicals growing fast, polls show Brazilians oppose changing the law. A survey by pollster VoxPopuli in 2010 showed that 82 percent reject decriminalization, while a Datafolha poll the same year put the figure at 72 percent.

Vandson Holanda, head of health for the Catholic Church in Brazil’s northeast, said there was no chance the Church would shift its position on abortion because of Zika.

Suspected cases of microcephaly have topped more than 4,000 – with more than 400 of those confirmed so far – since Zika was first detected in April. Around one-third of the suspected cases are in Pernambuco state around Recife.

The figures, which compare with around 150 cases across Brazil in a normal year, show no signs of slowing.

While there is no scientific proof of a connection between Zika and microcephaly, the World Health Organization (WHO) declared the outbreak a global emergency this month, citing a “strongly suspected” link. The virus has spread to 26 countries in the Americas since arriving in Brazil.

Women’s rights groups in Brazil such as Anis plan to appeal to the Supreme Court to relax Brazil’s abortion laws. They hope to build on a successful case in 2012 that legalized abortion for anencephaly, where the fetus develops without a major part of its brain and skull.

Given the difficulty of identifying microcephaly before the final weeks of pregnancy, Sinara Gumieri, a legal advisor to Anis, said the group would petition the court to legalize abortion for women diagnosed with Zika whose child was at risk of the condition, even if it is not diagnosed in the fetus. She admitted it would be difficult.

The doctors who led the anencephaly campaign in 2012 do not expect its success to be repeated.

“It’s completely different,” said Eugenio Pita, a doctor in Recife who performed legal abortions through the public health system for 20 years. “With anencephaly, the baby does not live; an abortion is only speeding up the inevitable. Babies born with microcephaly usually survive.”

CONSERVATIVE CONGRESS TIGHTENING LAW

Legislative reforms seem even more unlikely. A 2014 election returned a more conservative Congress, packed with Evangelicals, who account for roughly a fifth of Brazil’s 200 million people.

The speaker of the lower house, Eduardo Cunha, elected with the backing of Evangelical congressmen, has proposed legislation to make it harder to get an abortion in cases of alleged rape, sparking protests across Brazil last year.

Hundreds of Brazilian women die or are seriously injured each year in botched illegal abortions involving improvised equipment — mostly women not wealthy enough to travel abroad or pay for a proper doctor.

“Illegal abortions bring with them serious risks, the complications of which we have to pay careful attention to,” said Jailson Correia, Recife’s health secretary, calling for a national debate on liberalizing the law.

So far, there is inconclusive evidence that Zika has led to a rise in abortions. The website Women on Web, an Amsterdam-based charity that has offered to send free abortion pills to pregnant women infected with Zika, said email requests from Brazil asking about the service tripled last week.

The pills can be used to terminate pregnancy in the first 12 weeks.

But a for-profit online service, Aborto na Nuvem, said it reported no change beyond a usual 15-20 percent monthly increase the site has registered since it launched last year. Its co-founder, Heinrick Per, said the service was mainly used by wealthy Brazilians and he did not expect to see a rise because of Zika.

DETECTED LATE

With state-of-the-art equipment, experts say signs of microcephaly may be detected from about 24 weeks but it is impossible to determine how severe a case it might be. In Brazil, if identified before birth at all, it is usually registered at 30 to 32 weeks, by which time most doctors will not perform an illegal abortion.

“After 12 weeks it is hard to find a doctor to do an illegal abortion in Brazil. After 24 weeks, it’s impossible,” said Dr Elias Melo, a leading obstetrician at Hospital das Clinicas in Recife.

Though they are rarely prosecuted, doctors can face up to 10 years in prison.

“It’s not just a legal thing, it is cultural as well,” Melo said, noting that by 30 to 32 weeks you have a 2 kilogram (4.4 lb) baby that could survive if removed from the womb.

Complicating matters, as many as 80 percent of people with Zika do not show symptoms and there is no quick and reliable test for the virus widely available.

As a result, some women may opt for preemptive abortions early in pregnancy to avoid the risk of microcephaly, experts say.

French historian of science Ilana Löwy draws parallels with rubella in Britain and France in the 1950s, when abortion was illegal yet the number of terminated pregnancies rose dramatically.

Yet unlike with rubella, where up to 85 percent of fetuses infected in early pregnancy develop defects, doctors so far have no proof that Zika causes microcephaly, let alone an idea of its likelihood.

“Half of my 50 patients had Zika-like symptoms at some stage of their pregnancy,” said Melo. “Not one of them had a child born with microcephaly.”

Still, a dramatic rise in microcephaly cases could put a huge burden on poor families and public health services already under strain.

At a hospital in Recife, Gabriela Falcao cradles her 2 month old baby who was born with microcephaly and twisted legs as she waits to see a doctor.

“If I could go back, I still wouldn’t have an abortion,” she said. “I hold out hope my baby will grow to be like other kids.”

(Additional reporting by Ueslei Marcelino; Editing by Daniel Flynn and Kieran Murray)