Table 1a.

Descriptive characteristics of cohorts currently contributing to the I4C data pool.

Country/ Recruiting years	Study title (Acronym)	Cohort description	Pre-natal follow-up time points (weeks gestation)	Age at Post-natal follow-up time points	Method/s of follow-up
Australia* 1988-1995	Tasmanian Infant Health Study (TIHS) 20	■ Birth cohort ■ 10,625 live births ■ Recruited from 6 obstetric hospitals in the state of Tasmania, Australia ■ Eligibility: Infants born from January 1, 1988 to October 31 1992, resident in Tasmania, not placed for adoption and assessed as having a greater risk associated with Sudden Infant Death Syndrome (SIDS) as determined by a predictive score that included maternal age, male gender, birthweight and season of birth (March-April, May-June, August-February), duration of second stage of labor and intention to breast feed ■ Cohort represents a one in five sample of all births considered at higher risk of SIDS in Tasmania, Australia ■ Study staff conducted interviews four days post-natal in the hospital, at home and via telephone.	n/a	■ 4 weeks ■ 10-12 weeks	■ Home visits ■ Phone interviews ■ Record linkage
Denmark* 1996-2002	Danish National Birth Cohort (DNBC) 17	■ Population-based cohort ■ 101,042 births (I4C sample =9,596‡) ■ Sample recruited from all pregnant women across 16 counties in Denmark at first visit to the GP ■ Eligibility: All pregnant women who at first GP visit planned to carry pregnancy to term and who spoke Danish sufficiently well to complete telephone interviews were invited to participate.	■ 12 ■ 30 ■ Birth	■ 6 months ■ 18 months ■ 7 years	■ CATI** ■ Linkage to health registries
Israel 1964-1976	Jerusalem Perinatal Study (JPS) 18	■ Population-based cohort ■ 92,408 live- and stillbirths and their parents ■ Eligibility criteria: all births to Israeli women residents of West Jerusalem ■ Women identified from compulsory notifications to District Health Office. ■ Data obtained from antenatal interviews, pediatric admissions to hospital and postpartum interviews.	For 1965-68 sub-cohort, 13,500 mothers 4th-5th month of pregnancy	■ Hospitalization ages 0-5 for sub-cohort ■ Military recruitment office age 17 for recruits.	■ Linkage with disease registries, death registries; hospitalization records ■ Military recruitment data
Norway* 1999-2008	Norwegian Mother and Child Cohort Study (MoBa)19	■ Population-based pregnancy cohort ■ 109,981 live-born infants (I4C sample =11,218 ‡) ■ Women at participating clinics across Norway, invited to participate in study based on request for ultrasound examination made by doctor or women recorded at Medical Birth Registry ■ Eligibility criteria: Voluntary participation at 17 weeks gestation.	■ 17 ■ 30 ■ Birth	■ 6 months ■ 18 months ■ 36 months ■ 5 years ■ 7-8 years ■ 13 years	■ Self-administered questionnaires ■ Linkages to health registries
UK* 1990-1992	Avon Longitudinal Study of Parents and Children (ALSPAC) 14,15	■ Multi-generational birth cohort ■ 14,541 pregnancies and 14,062 live-birth ■ Representative sample of pregnancy women resident in a geographical region of Avon in South West England ■ Eligibility based on expected date of delivery between 1st April 1991 and 31st December 1992 ■ Opportunistic recruitment approach. Media campaigns, visits to community locations, antenatal maternity health services promoted study and distributed 'Expression of interest' card encouraging women to contact the study.	■ 8 ■ 12 ■ 18 ■ 32 ■ Birth	■ 4, 8 weeks ■ 6, 8,15, 18, 21, 24 months ■ 3,4,5… to 15 years	■ Self-administered questionnaires ■ Clinical assessment ■ Record linkage
USA* 1959-1965	Collaborative Perinatal Project (CPP)16	■ Prospective, longitudinal study of prenatal women ■ 48,000 women and 60,000 births ■ Women enrolled from14 obstetrical and pediatric departments across twelve universities across the USA ■ Eligibility criteria: attended first antenatal visit at one of the participating departments and deemed eligible by the obstetrician invited to participate	n/a	■ 4, 8 months ■ 12, 36, 48 months ■ 5,6,7 years	■ Administered interviews by trained personnel
TOTAL MOTHER-CHILD PAIRS		388,118

^*Cohorts with prospectively collected biological samples

^**CATI= Computerized telephone interviews

^‡Numbers represent the data currently available at the IDCC on a random 10% sample of the non-cancer cohort plus all the incident cases of childhood cancer.