Associations between prenatal exposure to air pollution and infant growth trajectories in the first two years: Exploring potential sexual dimorphism and sensitive windows

Zhen-Hua Li; Si-Wei Dai; Si-Yu Zhang; Chen Sun; Jia-Hui Li; Kai Huang; Mao-Lin Chen; Guo-Peng Gao; Cheng-Yang Hu; Xiu-Jun Zhang

doi:10.1016/j.envres.2025.122322

Associations between prenatal exposure to air pollution and infant growth trajectories in the first two years: Exploring potential sexual dimorphism and sensitive windows

Environ Res. 2025 Jul 8;285(Pt 1):122322. doi: 10.1016/j.envres.2025.122322. Online ahead of print.

Authors

Zhen-Hua Li¹, Si-Wei Dai¹, Si-Yu Zhang¹, Chen Sun¹, Jia-Hui Li¹, Kai Huang², Mao-Lin Chen³, Guo-Peng Gao⁴, Cheng-Yang Hu⁵, Xiu-Jun Zhang⁶

Affiliations

¹ Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China.
² Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China; Department of Hospital Infection Prevention and Control, The Second Affiliated Hospital of Anhui Medical University, 678 Furong Road, Hefei, 230601, China.
³ Department of Gynecology and Obstetrics, Ma'anshan Maternal and Child Health Hospital, Ma'anshan, 243000, China.
⁴ Department of Child Health Care, Ma'anshan Maternal and Child Health Hospital, Ma'anshan, 243000, China.
⁵ Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China; MOE Key Laboratory of Population Health Across Life Cycle, No 81 Meishan Road, Hefei, 230032, Anhui, China; Department of Humanistic Medicine, School of Humanistic Medicine, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China. Electronic address: cy.hu@ahmu.edu.cn.
⁶ Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China; MOE Key Laboratory of Population Health Across Life Cycle, No 81 Meishan Road, Hefei, 230032, Anhui, China. Electronic address: zhangxiujun@ahmu.edu.cn.

PMID: 40639597
DOI: 10.1016/j.envres.2025.122322

Abstract

Background: The exposure-response association between prenatal air pollution and infant growth trajectories is unknown.

Objectives: This study aims to assess how single and mixed exposure to prenatal air pollutants influence early-life growth trajectories and to explore the potential for sexual dimorphism and sensitive windows.

Methods: This study conducted a longitudinal analysis of 2278 mother-infant pairs from Ma' anshan birth cohort in China. We used a satellite-based spatiotemporal model to assess prenatal exposure levels to six air pollutants. Standardized anthropometric assessment of infants at various time points. We assessed the association between prenatal exposure to air pollutants and anthropometric measurements at various time points, using generalized linear regression and linear mixed models. Additionally, we applied group-based trajectory modeling (GBTM) to determine weight-for-age (WAZ) growth trajectories for all infants and for infants of different sexes during the first 0-2 year. To estimate the relationship between prenatal air pollutants and WAZ trajectories and to explore potential sex differences and sensitivity windows, multivariate logistic regression models, WQS, BKMR, and DLNMs were used.

Results: Compared to the moderate-stable WAZ trajectory, exposure to air pollutants (excluding O₃) during the 2nd trimester was positively associated with an increased risk of a high-stable WAZ trajectory in female infants. The WQS and BKMR results also indicated that 2nd-trimester exposure to a mixture of air pollutants was associated with an increased risk of a high-stable WAZ trajectory in female infants, with SO₂ and NO₂ identified as key pollutants. Additionally, the 2nd trimester was identified as a sensitive window for the effects of PM_2.5, NO₂, SO₂, and CO on the high-stable WAZ trajectory in female infants.

Conclusion: Exposure to air pollution during the 2nd trimester is positively associated with the risk of the high-stable WAZ trajectory in female infants.

Keywords: Air pollution; Growth trajectories; Longitudinal analysis; Mixture approaches; Sensitive windows.