By Emily McGarvey, Mar.7: The number of pregnant women and girls who are suffering from malnutrition has soared by 25% in the last two years, the UN children's agency Unicef says.
The world's poorest regions, such as Somalia, Ethiopia and Afghanistan, have been most affected, its report finds.
Unicef estimates that more than one billion women and adolescent girls worldwide are malnourished.
It says recent crises including war and Covid have made it increasingly hard for them to get the food they need.
Unicef has urged the international community to make food security a priority, including supporting failing nutrition programmes.
It stressed the impact malnutrition is having on children's health.
The Unicef report found that one billion undernourished women and adolescent girls were "underweight and of short stature" as a result, according to data analysis of women in most countries in the world.
It also found that they suffered from a deficiency in essential micronutrients as well as from anaemia.
South Asia and sub-Saharan Africa "remain the epicentre of the nutrition crisis among adolescent girls and women", the report said.
It found that 68% of women and adolescent girls there were underweight, and 60% of those suffering from anaemia.
"Inadequate nutrition during girls' and women's lives can lead to weakened immunity, poor cognitive development, and an increased risk of life-threatening complications - including during pregnancy and childbirth," Unicef said.
Malnutrition could also have "dangerous and irreversible consequences for their children's survival, growth, learning, and future earning capacity", it added.
"Globally, 51 million children under two years are stunted. We estimate that about half of these children become stunted during pregnancy and the first six months of life when a child is fully dependent on the mother for nutrition," it said.
Unicef estimates that between 2020 and 2022, the number of pregnant or breastfeeding women suffering from acute malnutrition increased from 5.5 to 6.9 million in the 12 countries deemed to be in a food crisis.
These are Afghanistan, Burkina Faso, Ethiopia, Kenya, Mali, Niger, Nigeria, Somalia, Sudan, South Sudan, Chad and Yemen.
"Without urgent action from the international community, the consequences could last for generations to come," said Unicef chief executive Catherine Russell.
"To prevent undernutrition in children, we must also address malnutrition in adolescent girls and women," she added.
Unicef called for mandatory legal measures to "expand large-scale food fortification of routinely consumed foods such as flour, cooking oil and salt" to help reduce micronutrient deficiencies and anaemia in girls and women.