Abstract：
A growing number of studies have associated walkability and greenspace exposure with greater physical activity (PA) in women during pregnancy. However, most studies have focused on examining women\'s residential environments and neglected exposure in locations outside the home neighborhood. Using 350 person-days (N = 55 participants) of smartphone global positioning system (GPS) location and accelerometer data collected during the first and third trimesters and 4-6 months postpartum from 55 Hispanic pregnant women from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study, we examined the day-level effect of women\'s exposure to walkability and greenspace on their PA outcomes during pregnancy and in the early postpartum period. Moderate-to-vigorous physical activity [MVPA] minutes per day was assessed using accelerometers. Walkability and greenspace were measured using geographic information systems (GIS) within women\'s daily activity spaces (i.e., places visited and routes taken) recorded using a smartphone GPS and weighted by time spent. We used a generalized linear mixed-effects model to estimate the effects of daily GPS-derived environmental exposures on day-level MVPA minutes. Results showed that women engaged in 23% more MVPA minutes on days when they had some versus no exposure to parks and open spaces in activity spaces (b = 1.23; 95%CI: 1.02-1.48). In addition, protective effects of daily greenspace and walkability exposure on MVPA were stronger in the first and third trimesters, among first-time mothers, and among women who had high pre-pregnancy body mass index (BMI) and lived in least-safe neighborhoods. Our results suggest that daily greenspace and walkability exposure are important for women\'s PA and associated health outcomes during pregnancy and early postpartum.
摘要：
越来越多的研究将步行性和绿地暴露与怀孕期间女性更大的身体活动（PA）相关联。然而,大多数研究都集中在检查妇女的居住环境和忽视暴露在家庭社区以外的地方。使用350人日（N=55名参与者）的智能手机全球定位系统（GPS）位置和加速度计数据，在第一和第三个三个月和产后4-6个月从55名西班牙裔孕妇中收集的环境和发育风险和社会压力（MADRES）研究，我们研究了女性在孕期和产后早期暴露于步行和绿地对其PA结局的日间影响。使用加速度计评估每天中等至剧烈的身体活动[MVPA]分钟。可步行性和绿地是使用地理信息系统(GIS)在女性的日常活动空间(即，访问的地点和采取的路线）使用智能手机GPS记录并按花费的时间加权。我们使用广义线性混合效应模型来估计每日GPS衍生的环境暴露对日水平MVPA分钟的影响。结果显示，女性在活动空间中接触公园和开放空间的时间增加了23%（b=1.23；95CI：1.02-1.48）。此外,在孕早期和晚期，每日绿地和步行暴露对MVPA的保护作用更强，在初为人母的人中,在怀孕前体重指数（BMI）较高且居住在最不安全社区的女性中。我们的结果表明，每日绿地和步行暴露对女性的PA和相关的健康结果在怀孕期间和产后早期是重要的。
