If the child had more than one type of dominant childcare the one with the most hours was chosen as the dominant type. Dominant childcare was coded as: maternal (i.e., mother was the main caregiver), non-maternal home-based (i.e., care by nanny, child-minder or relative) or centrebased (i.e., care in nursery or preschool) for every month. While finer divisions could be made (e.g. between different types of home-based care, a large number of types would not have been suitable for the subsequent cluster analysis defining the prevailing type over time