The impact of nature on neonatal health in Wales (2008-2019): a retrospective longitudinal study

Abstract Background Our environment plays a role in our health. However, the relationship or direction of influence nature exerts on neonatal outcomes, such as birthweight is unclear. Additionally, because most studies in this field have utilised cross-sectional methods, it is difficult to infer causality between Green and Blue Spaces (GBS) and neonatal health. Our study aims to answer the question, “Is greater exposure to GBS associated with improved neonatal outcomes in Wales (2008-2019)?" Methods We carried out a retrospective longitudinal study using administrative data in the SAIL Databank. The study population were women who had singleton births in Wales between 2008 to 2019. We investigated birthweight as a continuous variable (in grams). Exposures were greenness surrounding a mother's residence (enhanced vegetation index (EVI)) (300m Euclidean buffer), and nearest and average distance (in metres) between a residence and a body of water (blue space) (1600m network buffer). Annual exposure values were recorded for the period 1-year prior to pregnancy, and the year of pregnancy. We utilised generalised linear models to carry out analyses. Results Our study consisted of 176 459 individuals. We observed an increase of 3.04g (95% CI 0.33 - 5.76g, p-value= 0.03) in birthweight for every 0.1-unit increase of greenness around a mother's home during the year prior to pregnancy, and a similar birthweight increase of 2.69g (95% CI 0.05 - 5.33g, p-value= 0.05) for greater greenness exposure during pregnancy. Further, we found no statistically significant relationship between birthweight and distance (nearest and average) to a blue space for either exposure windows. Conclusions Green space exposure before and during gestation is associated with positive changes in birthweight. Proximity to blue space showed no significant association with birthweight. We recommend further study on other neonatal outcomes and investigation into the effects of socio-economic factors on this relationship. Key messages • A mother’s green space exposure is positively associated with neonatal birthweight. • We found no statistically significant relationship between birthweight and blue space exposure.