Childbirth and pregnancy, rather than conflict, are the nation's biggest killers of girls and women.

"Many deaths are not reported, in part because 90 per cent of women give birth away from formal medical facilities and without the help of professionally trained assistants," it said.

Childbirth and pregnancy, rather than conflict, are the nation's biggest killers of girls and women.

"One in seven South Sudanese women will die in pregnancy or childbirth, often because of infections (from puerperal fever and retained placenta), haemorrhaging, or obstructed births, with a lack of access to healthcare facilities playing a large role in their deaths," SAS found.

"When we talk about security in South Sudan there is a tendency to focus on issues such as guns and militia groups. But real human security means protection from anything that threatens health and wellbeing. In South Sudan there is nothing that poses greater threat to a woman's life than getting pregnant," says SAS researcher Lydia Stone.

• Sudan