The China Birth Cohort-Environmental and Genetic Factors (CBC-EG) Study: Design, Aims, Protocol, Findings, and Prospects

Early life, including the embryonic period, is particularly vulnerable to environmental exposures. Previous studies have largely focused on the relationship between individual environmental factors and population health. In reality, individuals are exposed to multiple environmental factors, which together form an “exposome” that reflects the environmental influences on human health. Exposome-based analyses utilizing biological samples have been conducted in various countries to assess the impacts of environmental endocrine disruptors and other pollutants on maternal and fetal health during pregnancy, particularly in developed countries. However, large-scale cohort studies that comprehensively cover major maternal and fetal diseases during pregnancy to explore the environmental and genetic interactions affecting maternal and fetal health are still lacking in China. Currently, environmental exposure assessment and biomarker measurement are particularly complex, given the challenges posed by handling mixed exposure effects and the hidden threats posed by emerging contaminants. The China Birth Cohort-Environmental Genetic Factors (CBC-EG) study was established as a large, multicenter cohort study spanning 14 cities across China. A total of 101,437 pregnant women were recruited between 2013 and 2022. The objectives of this cohort study include analyzing the effects of environmental exposure levels and behavioral factors, monitored through external exposure assessments, on embryonic development and pregnancy-related diseases. Additionally, the study aims to explore the impact of environmental pollutants, monitored through internal exposure assessments, on embryonic development and pregnancy outcomes. A key focus of this research is to investigate the potential threats posed by emerging contaminants to maternal and fetal health, as well as to uncover environmental and genetic interactions and identify susceptibility loci.