On Tuesday 8 March, the 100th anniversary of international women's day, more than a thousand activists will be attending a rally on Washington's Capitol Hill as part of a global round of celebratory activities, demanding a better future for some of the world's poorest women.

With the spotlight placed firmly on women's rights, it's ironic that Republicans in the House of Representatives have chosen this moment to push through a resolution (19 February), which will, if it becomes law, have a devastating impact on women's health and reproductive rights in the developing world, as well as affect some of the poorest and most vulnerable women in the US.

Part of a package that Nancy Northup, the president of the Centre for Reproductive Rights, has termed "the most vicious attack on women's health and rights in several decades", the bill includes cutting funding to the Title X family-planning programme – affecting low-income families' access to contraception and sexual health services in the US – and in an international context, it is also demanding the reimposition of the hated "global gag" rule.

This draconian edict, forged by Ronald Reagan, stripped USAID funding from international NGOs that dared to convey any information about abortion, along with other aspects of family planning, such as contraception and HIV/Aids prevention, to the communities they worked in. Since Reagan imposed the gag in 1984, it has become the proverbial political football; overturned by the Clinton administration in 1993, reimposed by Bush in 2001 and rescinded by Obama in 2009.

Despite breathing a collective sigh of relief two years ago, international family-planning organisations were well aware they were on borrowed time. Such was the precarious nature of their work they found it almost impossible to implement policy, set up any long-term goals or even conduct research that would inform them of areas of need. Seven years of the gag had created a climate of censorship around reproductive health issues in the developing world; abortion was not discussed, so any existing stigma that was attached to it, especially in deeply religious and conservative communities, was compounded. Maternal mortality in these communities was also high, as desperate women denied access to clean, safe clinics often took matters into their own hands with tragic consequences.

For example, it is no coincidence that Nepal, which legalised abortion in 2002, has one of the highest maternal mortality rates in the developing world. According to Unicef, about 281 Nepali women per 100,000 live births die of complications during childbirth; a significant number of these can be attributed to unsafe abortion. As a direct consequence of the gag, the Family Planning Association of Nepal had USAID withdrawn after establishing three small abortion clinics in the Himalayan kingdom in 2002.

From Bangladesh to Zimbabwe, the gag's malign influence hampered access to life-saving reproductive supplies. In Ethiopia, the loss of US contraceptive supplies exacerbated an already critical shortage, leading to an increase in HIV infection rates among young women aged 15-24.

If the gag were to return, the damage it would inflict on fledgling international family-planning services cannot be underestimated. The bill needs the approval of the Senate and President Obama to become law, but there is a concern that because of the Republican majority in the House of Representatives, compromises will have to be made. On the centenary of international women's day, allowing this to happen would simply be tragic.