In 1990, researchers in Britain started collecting tissues and detailed information from more than 14,500 pregnant women about their health, relationships, work and home. Furthermore, after giving birth, the study leaders tracked the offspring development through surveys, clinical exams and biological samples. Data was collected on their eating habits, physiological development including puberty onset, and behaviors, to name a few. In the long term, the researchers are tracing how genetic and environmental factors in the children’s early years affect their later ones.