Ethnicity and birth outcome: New Zealand trends 1980–2001: Part 2. Pregnancy outcomes for Maori women

Abstract

While traditionally Maori perinatal mortality has been similar to that of other ethnic groups, rates of preterm birth, small for gestational age (SGA) and teenage pregnancy have remained high. To review current trends in preterm birth, SGA and teenage pregnancy for Maori during 1980-2001 and to highlight the major factors that have influenced Maori reproductive outcomes during this period. De-identified birth registration data from 1 189 120 singleton live births and 5775 stillbirths were analysed for 1980-2001. Outcomes of interest included preterm birth, SGA and late fetal death while explanatory variables included maternal ethnicity, age and NZ Deprivation Index decile. Trend analysis was undertaken for 1980-1994 and multivariate logistic regression was used to explore risk factors for 1996-2001. During 1980-1994, Maori women had the highest preterm birth rates of any ethnic group in New Zealand, but in relative terms, inequalities declined as a consequence of a non-significant 7% fall in rates being offset by a statistically significant 30% increase for the European/other ethnic group. Rates of SGA were also higher amongst Maori women but declined by 25% during the 1980-1994 period. In addition, Maori women experienced significant socioeconomic gradients in SGA, with risk for Maori women in the most deprived NZDep areas being double that of Maori living affluent areas. Paradoxically, while Maori women had high rates of teenage pregnancy, this did not confer additional risk for preterm birth or SGA during the 1996-2001 period. While high rates of teenage pregnancy amongst Maori women appear not to confer additional risk for preterm birth or SGA, the social consequences of early childbearing may well be significant. The persistence of elevated rates of preterm birth and large socioeconomic gradients in SGA amongst Maori suggest that broader social and policy interventions are necessary if Maori are to achieve optimal birth outcomes in the coming decades.