Donald Trump's pro-abortion funding ban has infuriated many global health organisations as they say it will unintentionally lead to more abortions and more deaths in Africa.
The US president signed the executive order to stop federal money going to international groups which perform or provide information on abortions during his first week in office.
Known as the "Mexico City Policy", or global gag rule by critics, it was no surprise that he reinstated it. First introduced by Ronald Reagan in 1984, it has been become a game of policy ping pong between Republican and Democrat presidents.
Supporters of the ban say it protects the fundamental right to life.
But some health workers in Africa say when it was last put in place under George W Bush in 2001, it had far-reaching consequences.
"Women could not have access to contraceptive services and so they were getting unintended pregnancies and that increased the number of unwanted pregnancies and as such they went to the backstreet to do unsafe abortions," says Kenyan gynaecologist Dr John Nyamu.
The policy blocks US funding to overseas organisations that "support or participate in the management of a programme of coercive abortion or involuntary sterilisation".
It even affects countries like Kenya – where abortion is illegal unless a mother's life is at risk – as some family planning clinics or organisations get their funding from US pro-abortion groups.
The Trump order goes even further than previous Republican administrations, which only targeted reproductive health services, by extending the ban to cover all global health assistance provided by all departments or agencies.
"By removing funding from organisations that also deal with malaria and other child health issues, the policy could threaten progress on many fronts, including efforts to reduce HIV-related deaths and new infections, and decrease childhood mortality through malaria prevention and treatment initiatives and immunisation programs," Medecins Sans Frontieres (MSF) said in a statement.
The medical charity does not receive US government funding – so is not affected by the policy – but it fears that women's lives could be endangered.
Unsafe abortion is one of the five main causes of maternal mortality, accounting for 13% of cases, according to the World Health Organization (WHO).
The Mexico City Policy is based on the US Republican party's pro-life position, which has resonance with much of socially conservative Africa, where abortion is largely illegal.
Abortion on demand can only be offered in four out of 54 African countries, according to the UN's World Abortion Policies report.
But the continent carries the biggest burden of unsafe abortions, according to the WHO.
Marie Stopes International's projections for Nigeria suggest the policy will have a big impact on women's health in Africa's most populous country.
"Without US funding, from 2017 to 2020, over 1.8 million unintended pregnancies will probably occur; more than 660,000 abortions will happen and over 10,000 maternal deaths will not be averted," says Effiom Effiom, country director for Marie Stopes in Nigeria.
The International Planned Parenthood Federation (IPPF) regional office in Africa says it will lose up to $100m (£80m) in US funding meant for sexual and reproductive health services for millions of women and girls who would otherwise go without these vital services as it refuses to abide by the gag rules.
"Over the years USAid has been a huge supporter of family planning – with a budget of over $600m per year. Reinstatement will mean that years of progress to increase access to essential services globally, will be lost," it said in a statement.
IPPF works with affiliates in 30 African countries including at least a dozen clinics in Kenya, five of which shut down the last time the Mexico City Policy was reinstated.
But it has struck a defiant note, saying it will work to bridge the funding and services gaps as the Dutch government has done with plans for an international fund to finance access to birth control in countries hit by the cuts.
"We cannot and will not – deny life-saving services to the world's poorest women," IPPF said.