The CHILD Study was originally proposed and powered to explore relationships and interactions between environment and genetics in the early-life development of allergies and asthma. However, data collection at 3 and 5 years was expanded to provide for the study of other chronic non-communicable diseases (NCDs), including obesity and diabetes, and as CHILD researchers follow our participants through to post-puberty, the clinical focus of the study will further expand to include neurodevelopment, and outcomes such as chronic obstructive disease and cardiovascular and metabolic disorders. The CHILD Study has thus become a major platform for the investigation of developmental origins of health and disease (DOHaD). Participants are characterised by their geographical and ethnic diversity.
The CHILD cohort is ethnically, environmentally, culturally and socioeconomically diverse. The participating children are well phenotyped, allowing researchers to identify chronic illness early in life, and participant retention rates have been excellent to date (over 90% at present). The genetic assays being generated from the cohort include genomic, epigenomic, gene expression, metabolomic, microbiome data (ITS, 18S, 16S, metagenomics, both microbiome in and on their body, as well as the microbiome associated with house dust, and the mother's milk if breastfeeding), plus a wide range of environmental data, socioeconomic data, mental health data, medical history, physiology, and chemical analytics data.
The CHILD study recruited 3623 pregnant women (mean gestational age at recruitment of 26.7 weeks), most partners and 3542 infants who met eligibility criteria after birth; of these, 3495 commenced the study. The cohort was recruited over a 3.5 year period. As of September 15, 2017, 3206 of the 3495 children were continuing (retention rate 91.7%). Expectant mothers planning to give birth at participating hospitals were invited to be part of the study, enrolling the mothers prenatally and their child at birth, with follow up, up to 5 years of age.