The Wirral Child Health and Development Study (WCHADS) was designed to find out why some children develop behaviour problems from an early age and what factors lead to them persisting. Assessments included exposure to stress during pregnancy or in early life, aspects of the parent-child relationship, genetic make-up, family and peer relationships, cognitive and language development, physiological development, poverty and social circumstances. Data collected is also ideal for examination of the earliest origins of other child mental health outcomes. Going into adolescence WCHADS has studied: social media use; friendships, bullying and isolation; physical activity levels and physical development; risky behaviours and physical and psychological changes associated with puberty.
Mothers and children in the extensive sample have completed multiple types of assessment at 20 weeks gestation, 9 weeks, 14 months, 3.5 years, 4½ – 5 years, 7 years and 9 years. Fathers were surveyed on six occasions and teachers at age 7 and 9. Families in the intensive sub-sample (see design section) completed additional interviews, observational assessments and experimental measures including emotional, physiological, social, behavioural, and cognitive development. These assessments were at 32 weeks gestation, 4 weeks, 7 months, 14 months, 2½ years, 4½ – 5 years, 7 years and 9 years of age. Of the original sample, after 14 waves of data collection, 909 families are still in contact with the study and remain eligible for follow-up.
Several of our publications have documented now widely cited findings of sex differences in associations between maternal prenatal depression, anxiety and cortisol and infant and child behaviours and physiology. These suggest sex depend prenatal influences on development. We have also replicated protective effects of maternal stroking, and ‘match-mistmatch’ effects of prenatal and postnatal stressors consistent with evolutionary hypotheses. Recent evidence also supports sex differences in mechanisms for psychopathology. We have contributed several papers to the emerging literature on heterogeneity in child conduct problems, of crucial importance to later mental health, with particular focus on callous-unemotional traits and child irritability.
The study employed a two-stage sampling strategy. First, the participants in our extensive sample were identified from consecutive first time mothers who booked for antenatal care at 12 weeks gestation between 12/02/2007 and 29/10/2008. Written informed consent was gained from 68.4%. Of this ‘extensive sample’ of 1286 women recruited at 20 weeks of pregnancy, 1233 subsequently had a live singleton baby and remained in the study at birth and so were eligible for postnatal follow-up. This ‘extensive’ general population sample was then used to provide a stratified simple random subsample, the ‘intensive’ sample (316 mothers), and both the extensive and intensive samples have been followed up in tandem, with the intensive sample completing more intensive measurement at certain time points. This two stage stratified design enables intensive measurement on a sub-sample of children to be completed whilst collection of other measures across the whole sample (extensive sample) allows a weighting back of the findings from the intensive subsample to give general population estimates. For original sampling and recruitment in the open access paper.
At age 3.5 all those children in the extensive sample whose parent reported that to have borderline or clinical levels of externalising problems on the CBCL or evidenced CU traits were approached to join in the intensive study waves at future follow-up waves from age 5 onwards.
Management and funding
The study is funded by Medical Research Council from recruitment in pregnancy to age 9.
Age 11-12 is ongoing, supported by CWP NHS Foundation Trust.
The study management team represents a multidisciplinary partnership between Investigators from four UK Universities, led by Prof Jonathan Hill at University of Reading and Prof Helen Sharp at University of Liverpool.
Accessing the data
Proposals to access the WCHADS dataset should be submitted as outlined in the WCHADS Data Access Policy document. This document describes the process in detail and outlines the governance procedures in place. A formal data sharing application form must be completed.
Researchers are encouraged to have an informal discussion with the WCHADS Investigators as a first step, prior to formal application. This will enable WCHADS to optimally support selection of measures that are able to answer research questions.
For contact details and links to the WCHADS Data Access Policy and data sharing application form, please visit the study website.