Maternal mortality in England and Wales 1970-1985: an analysis by country of birth.

OBJECTIVE: To determine the risk of maternal mortality in immigrants to England and Wales. DESIGN: Analysis of death registrations, 1970-1985, by country of birth. SETTING: England and Wales. POPULATION: Women dying in England and Wales during pregnancy, childbirth or the puerperium, or dying from malignant tumour of the placenta. MAIN OUTCOME MEASURES: The risk of dying in pregnancy, childbirth or the puerperium, adjusted for age and year of death, and the risk of cause-specific death, adjusted for age, in immigrants compared with women born in England and Wales. RESULTS: Women born in West Africa (relative risk 10.3; 95% CI 8.0-13.2) and the Caribbean (4.6; 3.8-5.7) were at very elevated risk of maternal death and of the main causes of death. Women from Southern Asia (1.6; 1.3-2.0) and "Europe and the USSR' (1.7; 1.2-2.3) were at moderate risk. Adjustment for year of death increased the estimates of risk and women born in the "Rest of the World' and Scotland were at significantly elevated risk. CONCLUSIONS: An increased incidence of obstetric conditions in immigrant groups may account for the elevated risk but it is also possible that differences in care may account for some of the additional risk. The pattern of increased risk does not appear to be explicable by the parity or social class distribution of immigrants as far as data are available on these. Research is required into the aetiology of the differential incidence of obstetric disease. The collection of routine mortality data which include maternal reproductive and social factors would elucidate the significance of such factors to maternal health. Further investigation into possible differences in the process of antenatal care between immigrants and non-immigrants is required, and into whether this affects the risk of maternal mortality.