In addition, all children in the DNBC had also been invited to complete a follow-up web-based questionnaire at 11 y of age.
Information on prenatal PFAS exposure was available from measurements in two other independently sampled DNBC subcohorts (Figure 1).
The blood samples collected in the DNBC were transported to the biobank by ordinary mail that could subject them to measurement errors resulting from processing delay (Bach et al.
To assess possible bias due to subject selection for the LDPS, we first compared the PFAS levels in this sample with those in a previous DNBC study that randomly sampled live-born singleton children at birth such that the study was unaffected by loss to follow-up (Liew et al.
On the contrary, the DNBC, where PFOS exposure levels (median: 33 .18 ng/mL) are considerably higher than ours, prenatal exposure to PFOS and PFOA was nonsignificantly associated with self-reported lower BMI (n = 811), overweight, and WC (n = 804) at age 7 (Andersen et al.
The opposite pattern was seen in DNBC, where prenatal PFOA exposure (median: 5 .
was conducted in accordance with the Helsinki Declaration and approved by the Danish ethics committee.
Most of the participating women were born in the country of the cohort in which they participated (ranging from 100% in DNBC to 62.2% in ABCD).
The ORs changed very little after exclusion of the DNBC, of women who moved, and of women who participated with more than one pregnancy, and after additional adjustment for nationality and SHS.
2005) DNBC Danish National Birth Denmark Cohort (Olsen et al.
(a) Mother Child Cohort T1 T2 T3 Birth PoStnatal Birth ABCD B ALSPAC B,U B,U B,U P H.N CB ArcRiSk-Norway B,U B, U, B, U, BM CB.B.M H BAMSE BiB B,U CB Co.N.ER B CB Czech B,P CB DARC CB DNBC B B CB DuiSburg B B, U, BM CB EDEN B,U,S H, BM, CB, H, P M ELFE B, U, CB, CT, BM.
The detailed designs of the DNBC
and the PFC study nested in the DNBC
have been described previously (Fei et al.