Exposure to greenspace and birth weight in a middle-income country.

An emerging body of evidence has associated exposure to greenspace during pregnancy with improved fetal growth; however, all available studies have been conducted in high-income countries and the available evidence evaluating such an association for visual access to greenspace, use of green spaces and indoor plants is non-existent. We aimed to evaluate the association between a comprehensive array of indicators of exposure to greenspace during pregnancy, including the aforementioned indicators, and birth weight, in a middle-income country and evaluating air pollution and visual access as possible mechanisms underlying the association. This study was based on 301 pregnant women residing in Su et al. (2019). For each pregnant woman, we characterized exposure to residential surrounding greenspace, visual access to greenspace, residential proximity to green space, use of green spaces, and the number of plant pots at home. We used linear regression models adjusted for relevant covariates including measures of socioeconomic status. We found positive associations of maternal exposure to residential surrounding greenspace across a 100 m buffer, frequent viewing of greenspace through the window, percentage of window area covered by greenspace, residential proximity to any green space regardless of its area, time spent in public green spaces and total time spent in public and private green spaces with birth weight. We also observed positive associations of maternal exposure to residential surrounding greenspace across 300 m and 500 m buffers, residential proximity to a green space with an area ≥5000 m2, and indoor plant pots with birth weight, but none of these associations were statistically significant. The magnitude of the associations tended to be higher among parents with lower socioeconomic status. Mediation through air pollution or visual access was not established. Findings from this study suggested a positive role of different aspects of exposure to greenspace during pregnancy on birth weight in a middle-income country.