Pregnant women resident in Avon, UK with expected dates of delivery between 1st April 1991 and 31st December 1992 were invited to take part in the study, and the initial number of pregnancies enrolled was 14,541, including 13,988 children who were alive at 1 year of age. After additional recruitment efforts, the total sample size for data collected after the age of seven is 15,447 pregnancies, from which 14,901 children were alive at 1 year of age. Study data were collected and managed using REDCap electronic data capture tools hosted at the University of Bristol (31). The study website contains details of all the data that is available through a fully searchable data dictionary and variable search tool (http://www.bristol.ac.uk/alspac/researchers/our-data/). Ethical approval for the study was obtained from the ALSPAC Ethics and Law Committee and the Local Research Ethics Committees. Consent for biological samples has been collected in accordance with the Human Tissue Act (2004). Full details on data collection have been previously published (32, 33). The current study includes n=5,214 unrelated EUR participants with available genotypic data and measurements collected at ages 16–28.
