Regional patterns of infant mortality caused by lethal congenital anomalies.

PURPOSE To assess the regional patterns of infant mortality due to lethal congenital anomalies, and the potential reasons for the regional patterns. METHOD The study analyzed 2,507 infant deaths due to lethal congenital anomalies among 1,178,452 live births in 9 of the 12 Canadian provinces and territories from 1990 to 1995 recorded in Statistics Canada's live birth and death data bases. RESULTS Compared with the province of Quebec, congenital anomaly-attributed infant mortality was higher in Newfoundland, Saskatchewan, and Alberta. These differences in infant mortality were substantial for cardiovascular system anomalies and especially anencephaly. For infant mortality due to chromosomal anomalies, however, there was little inter-provincial variation. CONCLUSIONS Despite substantial recent reductions in lethal congenital anomaly-attributed infant mortality, there remain major regional variations in infant mortality caused by certain forms of congenital anomalies including anencephaly and cardiovascular system anomalies.