Unicef and WHO report that one in seven newborns weighs less than 2.5 kilos when it comes to birth, mostly in poor countries. This low birth weight has an impact on their growth and health.
In 2015, 20.5 million children came into the world weighing less than 2.5 kilograms, or about one in seven births worldwide. Nearly 90 percent of these births occur in low- and middle-income countries, including South Asia and sub-Saharan Africa, a new study published in the journal reveals. The Lancet Global Health.
Co-produced by the London School of Hygiene and Tropical Medicine, Unicef and the World Health Organization (WHO), this work highlights the impact of low birth weight on the future health of children. According to their authors, low birth weight babies "are at greater risk of stunting and later experiencing health problems, including chronic conditions such as diabetes and cardiovascular disease". They also present a higher risk of mortality. Indeed, more than 80% of the 2.5 million newborns who die every year in the world are underweight at birth, especially because of their prematurity.
Large regional disparities
To reach this conclusion, from 2000 to 2015, researchers examined national government databases and national surveys to estimate prevalence and monitor trends in underweight. In total, data were collected from more than 281 million births. However, the authors note that 47 countries (including 40 low- and middle-income countries that account for nearly one quarter of all births worldwide) did not have sufficient data.
The results highlight significant differences between low- and middle-income countries and rich countries. In these, low birth weight is often associated with premature birth. For Dr. Hanne Blencowe, who participated in the study, this prematurity can have multiple explanations, including "advanced age of the mother", but also "smoking, unjustified use of caesarean section or treatments that favor fertility, which increases the probability of multiple births. "
One of the lowest underweight rates in 2015 was estimated in Sweden (2.4%). This figure is around 7% in some high-income countries. In retail: 8% in the United States, 7% in the United Kingdom, 6.5% in Australia or 5.7% in New Zealand.
A low birth weight in two takes place in South Asia
The researchers also noted that the fastest growing regions are those with the highest number of low birth weight babies. This is particularly the case in South Asia and sub-Saharan Africa, which recorded annual decreases of 1.4% and 1.1% respectively between 2000 and 2015.
Nevertheless, the total number of live births of low birth weight children has actually increased in sub-Saharan Africa from 4.4 million to 5 million babies, mainly because of demographic trends (such as fertility and childbirth). migration). Similarly, South Asia still accounts for almost half of the births of low birth weight children worldwide, with an estimated number of 9.8 million in 2015.
"Underweight at birth is a complex clinical entity composed of intrauterine growth restriction and premature birth," says Dr. Mercedes of Onis of the WHO. "Therefore, the reduction of low birth weight requires an understanding of the underlying causes in a given country, for example, in South Asia, a large proportion of babies born with low birth weight are born at birth. term, but with intrauterine growth retardation, which is associated with maternal undernutrition, including maternal growth retardation. "
For international action against underweight
In 2012, the 195 WHO Member States pledged to reduce the prevalence of low birth weight by 30 per cent by 2025, compared to 2012 rates. These estimates are the first of their kind revealed that the prevalence of low birth weight worldwide decreased slightly from 17.5% in 2000 (22.9 million low-birth-weight live births) to 14.6% in 2015 (20.5 million).
However, the study indicates that at the current rate of progress - with an annual 1.2% decrease in low birth weight between 2000 and 2015 - the world will be well below the annual reduction rate of 2 , 7% required to reach the WHO target of reducing the prevalence by 30% between 2012 and 2025.
Hence the need "to invest more and act to accelerate progress, understanding and addressing the key factors of low birth weight throughout life," argue the authors of the report. 'study. "Despite clear commitments, our estimates indicate that national governments are doing too little to reduce low birth weight.We have seen very little change in 15 years, even in high-income settings where low birth weight is often due to prematurity, "says Dr. Blencowe. "Achieving the global nutrition goal of a 30 percent reduction in low birth weight by 2025 will require more than doubling the pace of progress."
The authors of the study call for international action to ensure that all babies are weighed at birth, to improve clinical care and to promote public health action on the causes of low birth weight. to reduce mortality and disability.