On Monday 23 January 2017, three days after he was inaugurated into the White House, Donald Trump signed an executive orderthat put the lives of millions of women around the world at risk.

The reintroduction of the Mexico City policy – or “global gag rule” as it’s commonly known – banned overseas NGOs from receiving US federal funding if they provided any abortion services. While aid organisations were braced for the move (the gag rule, introduced by Ronald Reagan in 1984, has been reintroduced and rescinded by Republican and Democrat governments respectively), they were not prepared for it to be extended to cover all global healthcare programmes, instead of just family planning services.

The following day, the high-profile political fightback began. Lilianne Ploumen, the then Dutch minister for foreign trade and development cooperation, called on donors to try to plug the estimated $8.8bn (£7bn) hole that would be left when the global gag rule came into force later that year. The SheDecides movement was born.

A pledging conference in Brussels followed two months later, attended by more than 50 countries, which raised $200m for some of the major organisations that had refused to sign up to the gag order, such as the International Planned Parenthood Federation and Marie Stopes International.

But that was just the beginning. Funding pledges have now topped $450m, government ministers and foundations have became vocal champions of the cause and a manifesto has been written.

Crucially, though, SheDecides has morphed from a top-down urgent international response to Trump’s policies into a growing global grassroots movement campaigning for the fundamental rights of women and girls to have control of their own bodies, everywhere.

More than 50,000 individuals and 300 organisations have registered their support for the movement, and pledged to take action. On 2 March, SheDecides events were held in 19 countries, from India and Afghanistan, to Egypt and Namibia, and the US to Australia. In South Africa, 250 ministers, policymakers and young people from across the region met in Pretoria (more are expected in March 2019). In November, health ministers from the 16 countries in the Southern Africa Development Community (SADC) adopted a “groundbreaking” new sexual and reproductive health and rights strategy, with scorecards to mark progress, with encouragement and input from SheDecides experts.

“I’m proud as punch how it’s evolved, and surprised how it’s evolved,” says Robin Gorna, who has led the SheDecides support team since May 2017. “On one level the gag rule was not unexpected. We knew it was extremely likely. What was unexpected was the expansion and impact [it would have on the] global health systems.”

What was also unexpected was the scale of the reaction to it. “It was a gift to feminists in many ways,” adds Gorna. “What’s exciting about the SheDecides movement is we have lasted, grown and morphed and become part of the broader feminist conversations … and we’ve hooked into bigger conversations that have been going on for decades, about body autonomy and sexual and reproductive health and rights,” says Gorna.

“We said in the beginning we didn’t want to be defined by Trump or one man’s bad policies, but it’s pretty remarkable that in September last year, when we brought champions together, it became clear we were no longer defined by him.”

At a local level, the draw of SheDecides is its power to build bridges between policymakers and young people, says Praise Mwesiga, a policy, advocacy and partnership officer at the Youth and Adolescent Health Forum in Uganda.

She recalls how policymakers and young people came together at an “open house” organised by the forum in Kampala. “We conducted a simple survey to see if people would buy into the idea of SheDecides. We got a lot of people interested in that.” Among those interested is the health minister Jane Aceng.

Mwesiga said the open house, and subsequent meetings, had raised the profile of some of the most contentious issues in Uganda – teen pregnancies, sex education and abortion. More young people have visited the forum and have been invited to speak at events.

“We were already working with young people,” says Mwesiga.

“But we embraced [SheDecides] because young people get to decide for themselves, have a choice, decide what to do with their bodies.”

Levi Singh, a youth strategy officer at the SRHR Africa Trust, in South Africa, says that although it is too early to assess the impact of SheDecides, he believes the SADC agreement couldn’t have been achieved without the weight of the movement.

Previous attempts to update the SADC sexual and reproductive health strategy had failed to deliver the wide-ranging vision campaigners had hoped, says Singh. But with ministers from South Africa and Namibia appointed SheDecides champions, he says they’ve started to talk more earnestly about change to policies and attitudes.

“The value is SheDecides helping to convene these processes.”

But, apart from the vision and collaborative opportunities, Lucy Masiye, the national president of YWCA in Zambia, says the “daring”, unashamedly bold name of the movement is a big draw. “That speaks to people. It’s a straight message. We are now boldly saying, ‘You have not been listening. Now this is what we have to do. A woman has to be heard.’”

Masiye says SheDecides is “very relevant for our association to be part of”, and she now has the job of taking its message to other organisations in Zambia and among YWCAs globally. “I’m excited because many more people have now come on board.

“The SheDecides movement started at international level, but the strength of it is its work as a local movement, which can at least help us bring to light the issues of women and children’s rights.”