The weight of an infant at birth (BW) is a crucial anthropometric measurement associated with infant mortality. Population BW statistics are important measures of overall population health. However, in low- and low-middle income countries (LMICs), BWs are not always measured, and when measured, they are often obtained and recorded inaccurately. Ideally, BW is measured within the first hours after delivery, before significant postnatal weight loss has occurred.
A newborn is defined as having normal BW if weight at birth is ≥ 2500 g. Low birth weight (LBW), as defined by the World Health Organization (WHO),is a weight at birth that is less than 2500 g (up to and including 2499 g). Infants with BW < 2500 g are further categorized into low birth weight (LBW), 1500–2499 g; very low birth weight (VLBW), 1000–1499 g; and extremely low birth weight (ELBW) < 1000 g. There is an inverse relationship between BW and mortality; newborns with LBW have a higher risk of neonatal mortality and are also at risk for stunting, poor neurodevelopment, and adult-onset diseases. Worldwide, an estimated 15–20% of all newborns weigh < 2500 g at birth. This translates to more than 20million births a year. The WHO has a goal to reduce the LBW rate by 30% by the year 2025. In certain regions, there has been an increase in the incidence of LBW deliveries. LMICs carry the highest burden of LBW infants. In 2015, three-quarters of the world’s LBW newborns were born in three regions: south Asia (47%), eastern and southern Africa (13%) and west and central Africa (12%).
In the recent past, data from high-income countries such as the United States and the United Kingdom recorded an increasing trend in mean BW, with a concurrent decrease in the prevalence of LBW. This finding prompts the question as to whether a similar trend is occurring in LMICs. Exploring temporal trends in BW are important to health care policymakers, especially if there are changes in or regression in medical care or nursing practices, or patterns related to health service access. For example, lack of, or late access to comprehensive antenatal care, which is common in LMICs, is correlated with a higher risk of pregnancy and newborn complications, including LBW. Improving rates of prenatal care is associated with decreases in the risk of premature birth and LBW.
A major challenge in monitoring the incidence of LBW is that about 60% of newborn babies in LMICs are not weighed nor have BW recorded. Population-based survey data often rely on retrospective maternal recall and modeled estimates, with statistical methods to adjust for underreporting and misreporting of BW. By contrast, the Global Network prospectively collects BW data in a population-based maternal and newborn health registry (MNHR) in six sites within five LMIC’s from sub-Saharan Africa (Kenya and Zambia), south Asia (Belgavi and Nagpur India; Pakistan), and Central America (Guatemala). The purpose of this study was to examine trends and regional variation of documented BW and LBW categories over time and to explore possible factors related to those trends in the Global Network MNHR.
By: Marete I, Ekhaguere O, Bann C, Bucher S, Nypngesa P, Patel A et al