Table 6.

Overview of the differences in design between several generations of parents-child cohorts for environmental health. This represents a schematic view aiming at making evolutions more visible.

Cohort Generation and Period	Recruitment Period and Participants	Biospecimens	Personal Measurements	Typical Example	Limitations
First generation (1990s and before) “Birth cohorts”	Birth or later. Children only generally.	After delivery only: maternal and possibly child spot biospecimens	None (questionnaire or model-based assessment exposure)	ALSPAC [87], GINI cohorts	Limited ability to investigate the effect of pregnancy exposures (besides atmospheric pollutants)
Second generation (2000-)	Pregnancy. Mother and child.	Pregnancy maternal spot (urine and blood) samples. Possibly DNA (mother, child, placenta) and child postnatal blood	Possibly use of a dosimeter during a single follow-up period	EDEN [88], INMA [89] cohorts	Limitations in terms of assessment of exposure to non-persistent compounds
Third generation (From after 2015)	Early pregnancy or preconception. Mother, father, child.	Repeated pregnancy maternal and child (possibly pooled) urine samples. Blood (mother, father, chord, offspring), DNA, RNA, possibly live cells (mother, father, offspring), placental sample, microbiome…	Repeated use of personal monitors for air pollutants, radiation, noise, temperature…. Detailed time space activity information.	SEPAGES cohort	Possible challenges to implement for a large sample size (1000-100,000 families), unless very large funding available