RESUMO
OBJECTIVE: To examine prevalence of novel newborn types among 541 285 live births in 23 countries from 2000 to 2021. DESIGN: Descriptive multi-country secondary data analysis. SETTING: Subnational, population-based birth cohort studies (n = 45) in 23 low- and middle-income countries (LMICs) spanning 2000-2021. POPULATION: Liveborn infants. METHODS: Subnational, population-based studies with high-quality birth outcome data from LMICs were invited to join the Vulnerable Newborn Measurement Collaboration. We defined distinct newborn types using gestational age (preterm [PT], term [T]), birthweight for gestational age using INTERGROWTH-21st standards (small for gestational age [SGA], appropriate for gestational age [AGA] or large for gestational age [LGA]), and birthweight (low birthweight, LBW [<2500 g], nonLBW) as ten types (using all three outcomes), six types (by excluding the birthweight categorisation), and four types (by collapsing the AGA and LGA categories). We defined small types as those with at least one classification of LBW, PT or SGA. We presented study characteristics, participant characteristics, data missingness, and prevalence of newborn types by region and study. RESULTS: Among 541 285 live births, 476 939 (88.1%) had non-missing and plausible values for gestational age, birthweight and sex required to construct the newborn types. The median prevalences of ten types across studies were T+AGA+nonLBW (58.0%), T+LGA+nonLBW (3.3%), T+AGA+LBW (0.5%), T+SGA+nonLBW (14.2%), T+SGA+LBW (7.1%), PT+LGA+nonLBW (1.6%), PT+LGA+LBW (0.2%), PT+AGA+nonLBW (3.7%), PT+AGA+LBW (3.6%) and PT+SGA+LBW (1.0%). The median prevalence of small types (six types, 37.6%) varied across studies and within regions and was higher in Southern Asia (52.4%) than in Sub-Saharan Africa (34.9%). CONCLUSIONS: Further investigation is needed to describe the mortality risks associated with newborn types and understand the implications of this framework for local targeting of interventions to prevent adverse pregnancy outcomes in LMICs.
RESUMO
OBJECTIVE: To estimate the burden of prematurity, determine gestational age (GA)-specific neonatal mortality rates and provide recommendations for country programs. STUDY DESIGN: Prospective data on pregnancy, childbirth, GA and newborn mortality collected by trained community health workers from 10 585 mother-newborn pairs in a community-based study. RESULT: A total of 19.4% of newborn infants were preterm; 13.5% were late preterm (born between 34 and 36 weeks of gestation), 3.3% were moderate preterm (born at 32 to 33 weeks) and 2.6% were extremely preterm (born at 28 to 31 weeks of gestation). Preterm babies experienced 46% of all neonatal deaths; 40% of preterm deaths were in late preterm, 20% in moderate preterm and 40% in very preterm infants. The population attributable fraction of neonatal mortality in premature babies was 0.16 for very preterm, 0.07 for moderately preterm and 0.10 for late preterm. CONCLUSION: In settings where the majority of births and newborn deaths occur at home and successful referral is a challenge, moderate and late preterm babies may be an important target group for home-based or first-level facility-based management.
