The Bill and Melinda Gates Foundation has said it would invest $1.5 billion in developing countries to support the health of pregnant mothers and their children and aid family planning and nutrition.
"The world must come together to save women's and children's lives," Melinda Gates said in a press statement on Monday.
She was attending the 2010 Women Deliver Conference in Washington, along with UN Secretary General Ban Ki-moon. Some 3,000 attendees gathered for the conference on maternal health to discuss improving the situation of women as part of the UN's Millenium Development Goals.
Gates, co-chair of the Bill and Melinda Gates Foundation, said it is critical to challenge the notion that large numbers of maternal and child deaths are inevitable, or even acceptable, in poor countries.
She cited examples of "existing, low-cost solutions - such as basic prenatal care, or educating mothers about the importance of keeping babies warm" - that can prevent maternal and infant deaths.
"Countries that have made women's and children's health a priority - and have invested in proven solutions - are achieving amazing results," she said.
She cited a study from the Institute for Health Metrics and Evaluation that showed the number of women dying from pregnancy-related causes has dropped by more than 35 per cent in less than 30 years - from more than 500,000 annually in 1980 to about 343,000 in 2008. Deaths among young children have also declined, from 11.9 million in 1990 to a projected 7.7 million for 2010.