An investment of under $5 per person on basic healthcare and contraception can help save millions of women and children every year, says a new study into pregnancy-related deaths.
Nearly six million children younger than five and 300,000 women died in 2015, according to research in The Lancet medical journal.
Ninety-five percent of maternal and child deaths occur in 74 low- and middle-income countries.
"Our analysis shows that expanding access to care to keep more mothers and children alive and healthy is feasible, and a highly cost-effective investment."
Four million lives could be saved each year by reaching 90 percent of those in need with basic services such as pregnancy and delivery care, childhood nutrition, and treatment for infectious diseases like pneumonia, diarrhea and malaria, said the team.
This was broken down into 1.5 million newborn deaths, 1.5 million child deaths, 149,000 newborn deaths and almost 850,000 stillbirths.
Access to contraception on its own, could reduce 67,000 maternal deaths, 440,000 newborn deaths, 473,000 child deaths and 564,000 stillbirths, they estimated.
The cost would be $6.2 billion (5.4 billion euros) in low-income countries, or $6.7 per person who needs it.
In lower-middle-income countries, the required amount is $12.4 billion or $4.70 per person, and in middle-income countries $8 billion or $3.90 per person.