Cheng-Yang Hu1, Xiao-Jing Yang2, Si-Yu Gui3, Kun Ding2, Kai Huang2, Yuan Fang4, Zheng-Xuan Jiang5, Xiu-Jun Zhang6. 1. Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China; Department of Humanistic Medicine, School of Humanistic Medicine, 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. 3. Department of Ophthalmology, The Second Affiliated Hospital of Anhui Medical University, 678 Furong Road, Hefei, 230601, China. 4. Department of Public Health, Erasmus University Medical Center, P.O. Box 2040, 3000, CA Rotterdam, the Netherlands. 5. Department of Ophthalmology, The Second Affiliated Hospital of Anhui Medical University, 678 Furong Road, Hefei, 230601, China. Electronic address: jiangzhengxuan@ahmu.edu.cn. 6. Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China; Center for Evidence-Based Practice, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China. Electronic address: zhangxiujun@ahmu.edu.cn.
Abstract
BACKGROUND: The amount of natural vegetation surrounding homes (residential greenness) has been proposed as a mitigation measure to buffer the adverse health effects of urban living, associated with promoting health and wellbeing including birth outcomes. This study aimed to systematically review the epidemiological evidence on the association of residential greenness with birth outcomes and quantitatively provide summary effect estimates of the current literature. METHODS: We extensively searched epidemiological studies related to residential greenness and birth outcomes in three electronic databases (EMBASE, Web of Science, and PubMed) using terms related to residential greenness and birth outcomes before July 10, 2020. Summary effect estimates of residential greenness on birth outcomes including SGA (small for gestational age), PTB (preterm birth), LBW (low birth weight), and birth weight were calculated for each 0.1 unit increase in residential greenness exposure, as well as comparing the highest to the lowest categories using random-effects meta-analyses. We assessed the risk of bias of each individual study, and the overall quality of the body of evidence and level of evidence for each exposure-outcome were also evaluated. RESULTS: The initial search identified 161 studies, of which 29 studies were finally included. Meta-analysis for continuous exposure suggested that an increase in residential greenness, measured by NDVI (normalized difference vegetation index) with different buffer sizes, was generally associated with higher birth weights ranging from 7.99 g [95% confidence interval (CI) = 4.29-11.70] to 15.35 g (95% CI = 11.41-19.29) and lower odds of LBW ranging from 0.79 (95% CI = 0.65-0.96) to 0.93 (95% CI = 0.86-1.00), but associations between residential greenness and PTB or SGA were not significant. When introducing the exposure as high versus low categories, similar results were found. The overall evidence for each exposure-outcome combination was considered to be of "moderate" certainty. CONCLUSIONS: This study indicated a potential positive association between residential greenness and several birth outcomes. However, because of the moderate to high between-study heterogeneity, further studies with better adjustment of covariates, improved residential greenness assessment in a longitudinal approach throughout pregnancy rather than a cross-sectional approach at time of delivery, and accounting thoroughly for socioeconomic status, are warranted to replicate these findings as well as to explore in greater detail in their implications.
BACKGROUND: The amount of natural vegetation surrounding homes (residential greenness) has been proposed as a mitigation measure to buffer the adverse health effects of urban living, associated with promoting health and wellbeing including birth outcomes. This study aimed to systematically review the epidemiological evidence on the association of residential greenness with birth outcomes and quantitatively provide summary effect estimates of the current literature. METHODS: We extensively searched epidemiological studies related to residential greenness and birth outcomes in three electronic databases (EMBASE, Web of Science, and PubMed) using terms related to residential greenness and birth outcomes before July 10, 2020. Summary effect estimates of residential greenness on birth outcomes including SGA (small for gestational age), PTB (preterm birth), LBW (low birth weight), and birth weight were calculated for each 0.1 unit increase in residential greenness exposure, as well as comparing the highest to the lowest categories using random-effects meta-analyses. We assessed the risk of bias of each individual study, and the overall quality of the body of evidence and level of evidence for each exposure-outcome were also evaluated. RESULTS: The initial search identified 161 studies, of which 29 studies were finally included. Meta-analysis for continuous exposure suggested that an increase in residential greenness, measured by NDVI (normalized difference vegetation index) with different buffer sizes, was generally associated with higher birth weights ranging from 7.99 g [95% confidence interval (CI) = 4.29-11.70] to 15.35 g (95% CI = 11.41-19.29) and lower odds of LBW ranging from 0.79 (95% CI = 0.65-0.96) to 0.93 (95% CI = 0.86-1.00), but associations between residential greenness and PTB or SGA were not significant. When introducing the exposure as high versus low categories, similar results were found. The overall evidence for each exposure-outcome combination was considered to be of "moderate" certainty. CONCLUSIONS: This study indicated a potential positive association between residential greenness and several birth outcomes. However, because of the moderate to high between-study heterogeneity, further studies with better adjustment of covariates, improved residential greenness assessment in a longitudinal approach throughout pregnancy rather than a cross-sectional approach at time of delivery, and accounting thoroughly for socioeconomic status, are warranted to replicate these findings as well as to explore in greater detail in their implications.
Authors: Federico Zagnoli; Tommaso Filippini; Marcia P Jimenez; Lauren A Wise; Elizabeth E Hatch; Marco Vinceti Journal: Curr Environ Health Rep Date: 2022-07-20