National Health Service Health Scotland, Edinburgh, UK.
Centre for Research on Environment, Society and Health (CRESH), University of Edinburgh, Edinburgh, UK and.
Int J Epidemiol. 2018 Feb 1;47(1):146-155. doi: 10.1093/ije/dyx258.
Birthweight is an important determinant of health across the life course. Maternal exposure to natural space has been linked to higher birthweight, but stronger evidence of a causal link is needed. We use a quasi-experimental sibling study design to investigate if change in the mother's exposure to natural space between births was related to birthweight, in urban Scotland.
Amount (% area) of total natural space, total accessible (public) natural space, parks, woodlands and open water within 100 m of the mother's postcode was calculated for eligible births (n = 40 194; 1991-2010) in the Scottish Longitudinal Study (a semi-random 5.3% sample of the Scottish population). Associations between natural space and birthweight were estimated, using ordinary least squares and fixed effects models.
Birthweight was associated with the total amount of natural space around the mother's home (+8.2 g for interquartile range increase), but was unrelated to specific types of natural space. This whole-sample relationship disappeared in the sibling analysis, indicating residual confounding. The sibling models showed effects for total natural space with births to women who already had children (+20.1 g), and to those with an intermediate level of education (+14.1 g).
The importance of total natural space for birthweight suggests that benefits can be experienced near to as well as within natural space. Ensuring expectant mothers have good access to high quality neighbourhood natural space has the potential to improve the infant's start in life, and consequently their health trajectory over the life course.
出生体重是贯穿整个生命历程的健康的重要决定因素。母亲接触自然空间与更高的出生体重有关，但需要更强的因果关系证据。我们使用准实验性的兄弟姐妹研究设计来调查母亲在两次分娩之间接触自然空间的变化是否与苏格兰城市的出生体重有关。
在苏格兰纵向研究（苏格兰人口的半随机 5.3%样本）中，为合格分娩（n=40194；1991-2010 年）计算了母亲邮政编码周围的总自然空间（%面积）、总可达（公共）自然空间、公园、林地和 100 米内的开阔水域。使用普通最小二乘法和固定效应模型估计自然空间与出生体重之间的关联。
出生体重与母亲家周围的自然空间总量呈正相关（中值增加 8.2 克），但与特定类型的自然空间无关。这种全样本关系在兄弟姐妹分析中消失了，表明存在残余混杂。兄弟姐妹模型显示，对于已经有孩子的妇女的自然空间总量（+20.1 克）和具有中等教育水平的妇女的自然空间总量（+14.1 克）存在影响。
自然空间总量对出生体重的重要性表明，在自然空间内和附近都可以感受到益处。确保孕妇能够很好地进入高质量的邻里自然空间，有可能改善婴儿的生命开端，并因此改善他们在整个生命过程中的健康轨迹。
