Fig. 1From: Air pollution exposure and gestational diabetes mellitus among pregnant women in Massachusetts: a cohort studyStudy flow. Of 362,148 eligible births in Massachusetts from 2003-2008, we included 158,894–159,373 births in final analytic samples. Trimester-specific PM2.5 exposure estimates were missing in 0.3 % of cases due to missing daily estimates when data from satellite and/or monitoring stations were not availableBack to article page