Table 1

Characteristics of the studies on the relationship between air pollutant and gestational diabetes mellitus

SourceLocationYears of studyStudy design and duration of follow-upPopulation (n) and age (years) of participantsNOS
Choe et al12Rhode Island, USA2002–2012 (excluded July 2004 to December 2005)Retrospective cohort studyn=61 640 mother–infant pairs, singleton births to mothers aged 18 years or older and residing in Rhode Island during the study period7
Fleisch et al13Boston, Massachusetts, USA1999–2002Prospective cohort studyn=2093 second-trimester pregnant women without known diabetes7
Fleisch et al14Boston, Massachusetts, USA1 January 2003 to 31 December 2008Retrospective cohort studyn=159 373 primiparous women during the study period without pre-existing diabetes7
Hu et al15Florida, USA1 January 2004
to 31 December 2005		Retrospective cohort studyn=410 267 women who gave birth in Florida during the study period and without non-singleton deliveries, previous preterm births, or pre-pregnancy diabetes mellitus8
Lu et al16Chiayi City, Taiwan2006–2014Retrospective cohort studyn=3589 non-diabetic pregnant women during the study period7
Malmqvist et al17Scania, Sweden1999–2005Retrospective cohort studyn=81 110 women who had singleton deliveries during the study period8
Pan et al18Taiwan2004–2005Retrospective cohort studyn=19 606 women were included after the exclusion criteria were applied8
Pedersen et al19Danish National Birth Cohort1997–2002Prospective cohort studyn=72 745 singleton pregnancies without hypertension, pre-existing chronic hypertension, and diabetes before pregnancy7
Robledo et al20USA2002–2008Retrospective cohort studyn=219 952 singleton deliveries to mothers without pregestational diabetes8
Shen et al21Taiwan2006–2013Case–control studyn=6717 mothers as the cases of newly diagnosed GDM
n=6717 control mothers were selected		8
van den
Hooven et al22		Rotterdam, Netherlands2002–2006Prospective cohort studyn=7399 pregnant women who had a delivery date in the study period, 21–38 years8
Choe et al23New York City2008–2010Retrospective cohort studyn=256 372 deliveries without non-singleton births, reporting smoking during pregnancy and mothers with pre-existing diabetes8
Jo et al24Kaiser Permanente Southern California (KPSC) hospitals1 January 1999 to 31 December 2009Retrospective cohort studyn=239 574 pregnancies without pre-existing diabetes8

  • GDM, gestational diabetes mellitus; NOS, Newcastle-Ottawa Quality Assessment Scale criteria.