The ground-breaking study, Children of the 90s was set up in Bristol twenty one years ago. Since then, thousands of parents and children have answered more than four hundred million questions which have helped shape healthcare and policies across the country.
Here are some of the findings from the study;
Eating oily fish in pregnancy is associated with higher than average IQ in children
Growing up in an overly clean environment can contribute to asthma and allergies
15 minutes of exercise a day can reduce the risk of childhood obesity
Children who are encouraged to speak and read earlier on, have beter communication skills when they start school.
The study is being expanded to look at fathers and siblings in more detail.
We spoke to Professor George Davey-Smith who is the scientific director of the study.