Abstract
ObjectivePreterm birth is a major global public health issue. However, sex difference in incidence and the potential association with air pollution in these disparities have not been fully explored globally.MethodsThis study is a retrospective, cross-sectional secondary analysis based on the Global Burden of Disease (GBD) 2021 database. Indicators included incidence, disability-adjusted life years (DALYs), years of life lost (YLLs), age-standardized rates, age-standardized YLL rate, age-standardized DALY rate, age-standardized YLL percent (ASYP), and age-standardized DALY percent (ASDP). Analyses were stratified by sex, socio-demographic index (SDI), and 21 GBD regions.ResultsFrom 1990 to 2021, male infants consistently experienced higher rates of preterm birth and greater disease burden than females, though the male-to-female ratio gradually narrowed. Particulate matter pollution significantly contributed to the burden of preterm birth, with males experiencing a higher burden than females. In 2021, particulate matter pollution accounted for roughly 1.3 times the burden observed in females and contributed to 31.1% of male ASYP and 26.7% of ASDP. Household air pollution was a major contributor, and its impact on males and females was similar in proportional terms. Regional variation was marked, with low-SDI regions, particularly sub-Saharan Africa and South Asia, experiencing the highest burden. Sex-stratified analyses revealed that air pollution, particularly household air pollution, had a more pronounced impact on males in some regions.ConclusionsMale infants consistently face a higher risk and burden of preterm birth worldwide. Particulate matter pollution, particularly household air pollution, appears to be linked to these disparities, especially in low-SDI regions. These findings underscore the need for targeted interventions to reduce indoor air pollution and mitigate sex-based inequalities in preterm birth burden.