The Exposure and Health Examination Survey mother-child(ren) cohort profile

he Exposure and Health Examination Survey (EXHES) cohort aims to elucidate the impact of environmental exposures (the external exposome) and their biological markers (the internal exposome) on childhood health conditions, asthma and allergies, obesity, and cognitive development in particular. Utilizing singletons and twins helped differentiate environmental effects from genetic influences due to the shared genetic background in twins. The EXHES cohort includes 2356 mother-child pairs across 10 European countries, comprising 1945 singletons and 411 twins, with data collected during the crucial first 1000 days of life. Data were gathered through epidemiological questionnaires and biomarkers, including blood, urine, hair, and breast milk from mothers, and cord blood, placenta, and cord tissues from children. Findings confirm that twin pregnancies are linked with increased risks of pregnancy complications, preterm birth, cesarean delivery, low birthweight, maternal health problems during pregnancy and a lower risk of macrosomia. Moreover, mothers of twins were more likely to have asthma, while higher maternal education was associated with a lower likelihood of twin births. The EXHES cohort provides a robust framework to be adopted in other studies for comparing singletons and twins to better understand how the exposome affects early child development and health outcomes. This approach offers new insights into the interplay between environmental and biological factors in shaping long-term health.