Risks of adverse pregnancy outcomes among Inuit and North American Indian women in Quebec, 1985-97.

Abstract

We used Statistics Canada's linked stillbirth, live birth and infant death files to assess the risks of adverse pregnancy outcomes among Inuit and North American Indian vs. other ethnic women in Quebec, 1985-97 (1 125 462 singleton births). Mother tongue was used to define ethnicity, with the largest French language group as the reference. Main outcome measures are adjusted odds ratios (AOR) for preterm birth, small-for-gestational-age (SGA), stillbirth, neonatal and postneonatal death controlled for maternal age, education, marital status, parity, infant sex, community size, and community-level random effects using multilevel logit models. Inuit women had higher risks of preterm birth (AOR = 1.49, 95% CI [1.25, 1.78]) and immaturity-related infant mortality (AOR = 3.03 [1.36, 6.74]), while Indian women did not. Infants of Inuit (AOR = 0.39 [0.31, 0.49]) and Indian (AOR = 0.27 [0.24, 0.31]) women had substantially lower risks of SGA. Elevated risks of stillbirth were observed among Indian women [AOR = 1.53 (1.09, 2.15)], and of postneonatal death among both Inuit (AOR = 4.45 [2.74, 7.22]) and Indian (AOR = 1.86 [1.28, 2.70]) infants. Both Inuit and Indian infants had much higher risks of sudden infant death syndrome (SIDS) and infection-related mortality. Although the absolute risks of adverse outcomes declined from 1985-87 to 1995-97, the relative disparities between aboriginal and non-aboriginal women changed little over this period. We conclude that Inuit and Indian women have different risk profiles for adverse pregnancy outcomes, and that prevention of preterm birth among Inuit women, and of SIDS and infection-related infant mortality in both aboriginal groups, are important targets for future research and intervention.