Now we are born describes the cross-sectional data from the first nine months of our cohort children’s lives and the longitudinal changes from antenatal to nine months. This second report from the Growing Up in New Zealand study describes the development of the new generation of New Zealand children from before they were born (as described in Report 1: Before we are born) until they are nine months of age.The information was collated from face-to-face interviews and telephone interviews with mothers and partners of the Growing Up in New Zealand children over a 12 month period. It also presents information about the children's birth and immediate postnatal period, which has been brought together from multiple routine data sources to add to the information provided by the parents.