Table 1

Characteristics of the cohorts contributing to the HELIX cohort

CohortRecruitment in original cohortExclusions made during recruitmentYears of birthRegion covered by HELIXNo. of births in HELIX entire cohort
BiB, UK5 All pregnant women who attended the oral glucose tolerance test clinic at Bradford Royal Infirmary in weeks 26–28 of pregnancy.Women who planned to move away from Bradford before birth were excluded.2007–2010Bradford10 849
EDEN, France6 Pregnant women who attended prenatal care at the University hospitals of Nancy and Poitiers recruited before 24 weeks of amenorrhoea.Twin pregnancies, women with known diabetes before pregnancy, insufficient French language skills and intention to move away from the recruitment area were excluded.2003–2006Nancy and
Poitiers, urban areas
INMA, Spain7 Pregnant women who attended a prenatal care centre in the study region during weeks 6–10 of pregnancy.Women who resided or intended to deliver outside the study area, who were aged under 16 years, who had twin or multiple pregnancies, who had assisted reproduction or who had communication problems were excluded.2003–2008Gipuzkoa
KANC, Lithuania8 Pregnant women who attended one of four prenatal care clinics affiliated to the hospitals of the Kaunas University of Medicine during first trimester of pregnancy.Women who lived outside Kaunas municipality, had medical records of pregnancy induced hypertension and/or diabetes were excluded.2007–2008Kaunas4107
MoBa, Norway9 Recruitment at the first ultrasound (US) scan, ie, during the 17–18 weeks of gestation. All women who gave singleton births in the participating maternity units.None1999–2008Oslo11 095
RHEA, Greece10 Pregnant women who attended US examination before 15 week of pregnancy with residence in and near Heraklion at Crete.Women who were aged under 16 years or who had communication problems were excluded.2007–2008Heraklion1458
Total31 472
  • BiB, Born in Bradford; EDEN, Étude des Déterminants pré et postnatals du développement et de la santé de l’Enfant; INMA, INfancia y Medio Ambiente; KANC, Kaunus cohort; MoBa, Norwegian Mother and Child Cohort Study.