Just 1km away from the African Union conference centre, and the international evangelical church in Addis Ababa, the Kirkos health clinic feels far from the politicking and religious opposition that continue to stalk abortion – one of the most contentious global health issues.

Outside, a blue and white sign displays the range of services on offer. Safe abortion tops the list, stenciled in big bold letters, followed by HIV testing, family planning and infertility treatment. Inside, the clinic's orderly waiting room is already full. It's 8.30am. Most visitors are young, between 18 and 25 years old, and nurses talk candidly about sex.

While abortion remains a radioactive issue in the US, a number of developing countries have liberalised their abortion laws in recent years, often citing alarming public health statistics. Globally, the World Health Organisation estimates that 47,000 women die from unsafe, "back-alley" abortions each year, and millions more are left temporarily or permanently disabled.

In 2005, Ethiopia legalised abortion in cases of rape or incest, for all young women under the age of 18, and in a number of other situations. Guidelines from the ministry of health in 2006 went further, expanding the range of health facilities allowed to provide abortion services and instructing health workers that women seeking abortions do not have to provide proof of rape or incest, or of how old they are.

The Kirkos clinic, run by the NGO Marie Stopes International (MSI), saw up to 13,000 patients last year, more than 8,500 of whom seek abortions. Being able to offer and advertise a range of services is critically important, says Shewaye Alemu, area manager for MSI in Addis, the Ethiopian capital. It means women can walk into the clinic without disclosing to the world whether they are seeking an abortion, she says.

But despite having one of the most liberal abortion laws in Africa, progress on expanding access to services has been slow, particularly in rural areas. If the Kirkos clinic shows what is possible under Ethiopia's new law, it is still the exception rather than the norm.

Some 200km from Addis, in the West Arsi zone of Ethiopia's Oromia region, the Buta health post stands in a small valley.

Inside, the walls of the small, two-room building are covered with hand-drawn tables charting community progress on vaccinations, malaria treatment, use of contraception, and other targets. Staffed by a small team of community health workers, the Buta post serves more than 4,000 people in nearby villages and is one of thousands of such facilities built by the government to extend services into rural areas.

But while women visiting the health post can get their children vaccinated, have contraceptive implants fitted and deliver babies a woman seeking an abortion would have to travel dozens of kilometres to find someone to carry out the procedure.

Staff at the health centre, 8km away, the next rung up in Ethiopia's multi-tiered healthcare system, say the person trained to provide abortions left a year ago and has not yet been replaced. Women who arrive looking for abortion information and services are referred to the public hospital or NGO clinic in the towns of Awassa (19km away) or Shashamane (26km).

Figures from 2008, the most recent statistics, suggest just 27% of abortions were safe procedures carried out in health facilities. Many women remain unaware of their rights, and where they can access services. Stigma around abortion also persists, particularly for young and unmarried women, and the quality of care available varies dramatically across the country. In 2008, only two-thirds of health facilities were sufficiently equipped to provide basic abortion care, treatment for post-abortion complications, and antibiotics; just 41% of the primary care facilities on which most rural women rely offer basic abortion services.

According to some human rights lawyers and public health NGOs, Ethiopia is a prime example of how controversy about abortion in the US continues to limit women's access to safe services, even in countries where it is legal. While reproductive health issues and efforts to end maternal deaths have risen up the agenda of aid donors, very few are willing to fund abortion. The largest global health donor, the US Agency for International Development (USAid) attaches anti-abortion restrictions to all of its foreign assistance.

"There is increasing recognition by the international community of the impact of unsafe abortions on maternal mortality. But funding does not reflect this," said Manuelle Hurwitz, senior advisor on abortion at International Planned Parenthood Federation.

US funding flaws

The Buta health post is part of a massive USAid programme, which aims to reach more than half the country's population and help reduce maternal and child mortality by supporting integrated family healthcare. The programme does not fund safe abortion – though it does support some services for women suffering health complications following unsafe abortions.

Pathfinder, the US NGO that implements the USAid programme in Ethiopia, says this is a "missed opportunity" and that it is actively looking for other sources of funding so that abortion services can be offered too.

"Any primary health clinic that doesn't provide abortions is a missed opportunity," said Demet Güral, a physician and vice-president of programmes at the NGO. Even if women have access to contraception, there are always failure rates, says Güral, and it is essential they can access safe abortion if needed. "Especially for youth; most are not married, they have a future. How can you talk about family planning for youth and not talk about abortion? It's nonsense."

While US president Barack Obama repealed the 'global gag rule', which prohibited foreign NGOs from receiving US funding if they performed or promoted abortion, anti-abortion restrictions remain attached to US foreign assistance through a relatively obscure and often misunderstood amendment, attached to the US foreign assistance act.

The Helms amendment, first enacted in 1973, says no US aid can go towards abortion "as a method of family planning" or to "motivate or coerce any person to practice abortions". What this means is open to interpretation, however. In practice, USAid has implemented the Helms amendment as an absolute ban on abortion.

Liz Maguire, CEO of IPAS, a US-based NGO, says Ethiopia is "one of the best examples" of how these restrictions can impact on women's lives. "Abortion is the most neglected area in women's health," said Maguire, who worked for USAid for decades and was head of its population assistance programme during the Clinton administration. "Here, what's sad is that women are being discriminated against because they live in areas with USAid funding."

Güral said it is a sad fact that most of the world's deaths due to unsafe abortions happen in developing countries, where US foreign aid is a critical resource. Many NGOs shy away from working on abortion because they fear the 'global gag rule' could return, or are confused about which specific services are allowed under the Helms amendment, she added. "On the ground ... we have a 'let's not go there' feeling. That's the chilling effect," said Güral. "Of course this is affecting the lives of women."

• Claire Provost travelled to Ethiopia with Pathfinder