Optimal Gestational Weight Gain and Fetal Growth in Urban Environments: The Role of Residential Greenness

The influence of residential greenness on maternal gestational weight gain (GWG) and fetal intrauterine growth remains understudied. This study examined the impact of residential greenness on GWG and fetal intrauterine growth and assessed the mediating role of GWG. The research included 29406 births in Shanghai, utilizing the normalized difference vegetation index (NDVI) to measure greenness within a 500 m radius (NDVI-500). The analysis employed a generalized linear model to assess the impacts of residental greenness on GWG, fetal growth and birthweight, and a mediation analysis to explore GWG's role between greenness and fetal development. Results indicated that significant benefits were observed with increased greenness, where each 0.1 unit increase in NDVI-500 was associated with reductions of 9.4% (95% CI: 5.5%-13.2%) in the risk of head circumference undergrowth and 8.5% (95% CI: 4.8%-12.2%) in estimated fetal weight undergrowth. Additionally, each 0.1 unit increase in NDVI-500 was associated with reductions of 9.4% (95% CI: 5.1%-13.5%) and 9.2% (95% CI: 6.2%-12.0%) in the risk of inadequate and excessive GWG, respectively. Notably, total GWG mediated 17.5% of the relationship between NDVI-500 and the birth weight. These findings suggest that enhancing residential greenness could be an effective public health strategy to improve pregnancy outcomes by promoting fetal growth and managing GWG, with the GWG partially mediating these benefits.