The weight of invisibility
Authors: None The Lancet Global Health
Journal: The Lancet Global Health (2019)

On May 6, the BBC reported that a new baby had been born into the UK royal family. The first sentence of the bulletin gave the baby's sex, the second the delighted father's reaction, the third the time of birth, and the fourth the birthweight (a healthy 3200 g). That a baby's weight should be a notable concern goes without saying in most wealthy societies. Yet, as Hannah Blencowe and colleagues show in their Article presenting new figures on the burden of low birthweight worldwide, knowing the weight of babies at birth is still far from universal. Birthweight matters because of its strong association with neonatal health and survival, child growth, and non-communicable disease (NCD) risk in adulthood. Girls whose height and weight remain low into motherhood risk giving birth to another generation of nutritionally disadvantaged children. A birthweight of less than 2500 g—the WHO definition of low birthweight (LBW)—is an imperfect measure, since it conflates babies who are small because they are born preterm, those who reach full term but have had their growth restricted in utero, and babies who are both preterm and growth restricted. But although gestational age is even more predictive of risk than birthweight, the latter is much easier to measure. Recognising this, reducing LBW is one of the six targets set out by the WHO Comprehensive Implementation Plan on Maternal, Infant and Young Child Nutrition. The Plan set a target to reduce the global number of preterm births by 30% by 2025—a 3% relative reduction per year from 2012. How do Blencowe and colleagues' findings suggest that we are doing in terms of that target? Not at all well is the short answer. The authors estimate that 20·5 million LBW babies were born in 2015, representing 14·6% of all livebirths. This is a decrease from 2000 figures of 22·9 million and 17·5%, respectively, but only an average annual decline of 1·2%. Additionally, the global figure masks important differences between regions. For those with the highest-quality data, including North America, Europe, Australia, and New Zealand, prevalence (around 7% on average) has not budged in 15 years, yet between-country differences show the potential for improvement: Sweden's LBW prevalence was only 2·4% compared with Bulgaria's 9·6%. Rates have reduced by 1·1% per year in sub-Saharan Africa (to 14·0%) and by 0·8% in North Africa (to 12·2%), but still clearly remain much higher than those of high-income regions. Despite the large burden, data were most scarce and of the lowest quality for Africa. South Asia has seen the greatest decline (1·4%), but still has the highest prevalence (26·4%) and the largest absolute burden. What are the priorities, then, in terms of closing progress gaps and data gaps? First, it is important for governments to examine the causes of LBW, given that they differ by region. High-income countries will have a predominance of preterm births among their LBW figures, and these might be driven by maternal obesity, smoking, non-medically-indicated caesarean sections, or older maternal age. Social determinants of health and education are therefore likely to be key focus areas in these regions. In Africa, preterm birth is also the main driver, with a mix of adolescent pregnancy, maternal infections, and possibly genetic influences. In South Asia, however, about half of LBW is related to fetal growth restriction driven by undernutrition among girls, as well as maternal obesity, NCDs, anaemia, and exposure to tobacco smoke and indoor air pollution. A long-term multisectoral response to intergenerational nutritional and environmental insults, particularly for girls, is therefore imperative in South Asia, as is improved quality of antenatal care. Second, high-income and middle-income countries have made rapid progress in the care of LBW babies, reducing both deaths and disability. These survival gaps can and must be closed in low-income countries. Third, health professionals and advocacy groups should ignite demand for better birthweight data. With more births taking place in facilities, and given the minimal cost implications, weighing every baby at birth and having the data recorded in routine health information systems is not a monumental ask. And we should mean every baby, not just those born alive. The numbers being tracked currently exclude stillbirths (several of whom—at least in lower-income countries—are in fact born alive but die shortly after birth), so the real burden of LBW is likely to be higher than reported. Women and families should be empowered to demand a birthweight for their baby and an explanation of the possible cause and implications, should it be below 2500 g. Invisibility cannot be allowed to perpetuate a cycle of death and disadvantage. National, regional, and worldwide estimates of low birthweight in 2015, with trends from 2000: a systematic analysisAlthough these estimates suggest some progress in reducing LBW between 2000 and 2015, achieving the 2·74% AARR required between 2012 and 2025 to meet the global nutrition target will require more than doubling progress, involving both improved measurement and programme investments to address the causes of LBW throughout the lifecycle. Full-Text PDF Open Access