KIGALI (Reuters) – At midnight Valentine Uwingabire's back began to hurt. Her husband ran to tell Germaine Uwera, a community health worker in their village in the fertile foothills of Rwanda's Volcanoes National Park.

Equipped with a mobile phone from the local health centre, Uwera sent an urgent SMS text message and within a quarter of an hour, an ambulance had whisked Valentine to hospital. Minutes later Uwingabire's third child was born.

"We called our child Manirakoze, which means 'Thank God'," she told reporters, sitting outside her mud and bamboo house pitched in the shadow of Karisimbi volcano, home to some of the world's few remaining highland mountain gorillas.

Had it not been for Rwanda's new Rapid SMS service, Valentine would have been carried in agony, down the hill to the nearest town on an improvised stretcher. As is the case in much of Africa, fixed-line telephone networks are virtually non-existent outside of the capital and major cities.

The Rapid SMS scheme – a joint initiative between three UN organisations – is being tested in the Musanze District where 432 health workers have received mobile phones.

Health workers register pregnant women in their village via free SMS text messages and send regular updates to a central server in the capital, Kigali.

They are monitored during the pregnancy, and those at high risk brought in for check-ups.

Rwanda, Africa's most densely populated nation, is ranked among the world's worst for maternal mortality, according to UN data, and it is an important target for the global body's goal to reduce maternal deaths by 75 percent globally by 2015.