Around one in seven babies born worldwide had weighed less than 2500g (5.5 pounds) at birth, in 2015, says a report released by WHO.
More than 80% of the world’s 2.5 million newborns who die every year are of low birthweight.
“Low birthweight is a complex clinical entity composed of intrauterine growth restriction and preterm birth,” said the co-author Dr Mercedes de Onis from the Department of Nutrition at WHO in the press release.
Reducing low birthweight requires an understanding of the underlying causes in a given country, he said.
“For example, in Southern Asia a large proportion of low birthweight babies are born at term but with intrauterine growth restriction, which is associated with maternal undernutrition, including maternal stunting.”
“Conversely, preterm birth is the major contributor to low birthweight in settings with many adolescent pregnancies, high prevalence of infection, or where pregnancy is associated with high levels of fertility treatment and caesarean sections (like in USA and Brazil). Understanding and tackling these underlying causes in high-burden countries should be a priority.”
The study reports that although close to three-quarters of babies were born in Southern Asia and sub-Saharan Africa, the problem remains substantial in high-income countries involving Europe, North America, Australia and New Zealand. High-income countries have reported to show no virtual progress.
Low birth-weight babies who survive also tend to develop a greater risk of developmental and physical ill health later in life, including stunting, diabetes and cardiovascular disease, reports WHO.
In order to reduce the incidence of low birth weight WHO implements a comprehensive global strategy, which must include improving maternal nutritional status; treating pregnancy-associated conditions such as pre-eclampsia (hypertensive disease of pregnancy); and providing adequate maternal care, perinatal clinical services and social support.
The report was developed by experts from the World Health Organization, UNICEF and the London School of Hygiene & Tropical Medicine.