The 2006 Canadian Birth-Census Cohort.

BACKGROUND Evidence on socioeconomic and ethnocultural disparities in perinatal health in Canada tends to be limited to analyses by neighbourhood or for selected provinces. In 2010, the Canadian Institutes of Health Research awarded funding for a project on perinatal outcomes. This article describes the resulting 2006 Canadian Birth-Census Cohort Database. DATA AND METHODS From the Canadian Live Birth, Infant Death and Stillbirth Database, 687,340 records of children born in Canada from May 16, 2004 through May 15, 2006 to mothers whose usual place of residence was Canada were selected as in-scope births. Deterministic rules were applied to link each person on the birth record-child, mother, father-to 2006 Census data.The cohort was restricted to records linked to a long-form questionnaire, and a cohort weight was developed. Cohort rates (unweighted and weighted) for five birth outcomes-preterm birth, small-for-gestational age, large-for-gestational age, stillbirth, and infant mortality-were compared with rates for all in-scope births across birth characteristics. Cohort rates for these birth outcomes were examined across selected census characteristics. RESULTS Linkage rates were 91% for births surviving to age 1, 76% for stillbirths, and 80% for infant deaths matched to a birth registration. The cohort estimates were similar to those for all in-scope births, particularly after the cohort weight was applied. The cohort data produced plausible estimates of selected birth outcomes across maternal ethnocultural categories and levels of education. INTERPRETATION The 2006 Canadian Birth-Census Cohort data can help inform perinatal surveillance and research in Canada.