Study Design and Baseline Profiles of Participants in the Tianjin Birth Cohort (TJBC) in China

Background: To investigate the causal link between early-life exposures and long-term health consequences, we established the Tianjin Birth Cohort (TJBC), a large-scale prospective cohort in northern China. Methods: TJBC aims to enroll 10,000 families with follow-ups from pregnancy until children's six year-old. Pregnant women and their spouses were recruited through a three-tier antenatal healthcare system at early pregnancy, with follow-ups at midpregnancy, late pregnancy, delivery, 42 days after delivery, 6 months after delivery, and each year until 6 years old. Antenatal/ neonatal examination, biological samples and questionnaires were collected. Results: From August 2017 to January 2019, a total of 3,924 pregnant women have already been enrolled, and 1,697 women have given birth. We observed the prevalence of gestational diabetes mellitus as 18.1%, anemia as 20.4%, and thyroid hypofunction as 2.0%. In singleton live births, 5.6% were preterm birth (PTB), 3.7% were low birth weight, and 7.3% were macrosomia. Based on current data, we also identified maternal/paternal factors which increased the risk of PTB, including paternal age (OR 1.07; 95% CI, 1.01-1.14 for each year increase), vaginal bleeding during pregnancy (OR 2.82; 95% CI, 1.54-5.17) and maternal early-pregnancy BMI (OR 1.08; 95% CI, 1.01-1.15 for each kg/m2 increase). Conclusion: TJBC has the strength of collecting comprehensive maternal, paternal, and childhood information. With a diverse range of biological samples, we are also engaging with emerging new technologies for multi-omics research. The study would provide new insight into the causal link between macro/micro-environmental exposures of early life and short/long-term health consequences.

Automated summary

The Tianjin Birth Cohort (TJBC) is a large-scale prospective cohort study aiming to investigate the causal link between early-life exposures and long-term health consequences. The study plans to enroll 10,000 families in northern China and follow them from pregnancy until the children reach six years old, collecting various information and samples during the antenatal, neonatal, and childhood periods.