FETOTOX includes two large Danish birth cohorts – the Danish National Birth Cohort (DNBC) and the Aarhus Birth Cohort Biobank (ABCB) – and three smaller cohorts from Norway (MISA), Greenland (ACCEPT) and China (CHBC).

The FETOTOX project includes 4 linked substudies:

1. Toxicological analyses of PFCs/POPs in maternal and cord blood; their time trend levels and impact on steroid hormone and dioxin receptor functions, cellular stress and possible counteraction by trace elements.
2. POP/PFC levels in early pregnancy, waiting time to pregnancy (TTP), fetal growth and infant growth and development.
3. Comparisons of Danish birth cohort data with international birth cohorts.
4. Case-cohort study on PFC levels in maternal blood and the risk of child ASD, ADHD and CP. 

Substudies 1 and 2 are based on the ABCB and will include blood samples collected during the years 2008 to 2015 (time trend analysis also DNBC, see substudy 4).
Substudy 3 will compare ABCB data with birth cohort data from Norway (MISA collected from 2006 to 2009), Greenland (ACCEPT 2010 to 2013) and China (CHBC 2011 to 2015).
Substudy 4 is based on DNBC where the samples already were collected in the period 1996-2002.
Substudy 1 is experimental epidemiology and substudies 2, 3 and 4 are epidemiological studies.

Substudy 1 and 2: The toxicological biomarkers from substudy 1 will be analyzed for association with TTP and fetal and infant growth and development, determined in substudy 2.
Substudies 1, 2 and 3: Comparison of POP / PFC levels and birth outcomes (birth weight, length, head and abdominal circumference and gestational age at birth) for ABCB, MISA, ACCEPT and CHBC.
Substudies 1, 2, 3 and 4: Comparison of PFC levels over time including all involved birth cohorts (PFC time trend analyses 1996-2015).
A total of 1800 samples from ABCB and 1400 samples from DNBC are included in the FETOTOX project.