Perinatal outcomes among young Indigenous Australian mothers: A cross-sectional study and comparison with adult Indigenous mothers

Background: The teenage pregnancy rate is high among Indigenous Australian women, yet little is known about their pregnancy outcomes. Moreover, against a background of extreme social disadvantage, the relative importance of age as a risk factor for adverse outcomes among Indigenous pregnancies is unclear. We compared perinatal outcomes for Indigenous teenagers (<20 years) with adult Indigenous women (20-34 years), and described outcomes in subgroups of teenagers.

Methods: Data were analyzed for 2421 singleton births to Indigenous women aged <35 years in Australia's Northern Territory from 2003 to 2005. Regression was used to assess the effect of young maternal age on normal birth, healthy baby, preterm birth, low birthweight, special care admission, and mean birthweight, adjusting for covariates.

Results: Three-quarters of teenagers and 62% of adult mothers lived in remote areas. Smoking rates were around 50% in both groups. Teenagers were more likely to have a normal birth than adults (adjusted odds ratio 1.78 [95% CI 1.35-2.34]). The groups did not differ for healthy baby, preterm birth, or low birthweight. Babies of teenagers weighed 135 g less than those of adults; however, adjustment for covariates eliminated this difference. Examination of teenage subgroups (≤16 years and 17-19 years) revealed risk behaviors being higher for 17-19 years olds than for the younger group, and more prevalent among urban-based mothers.

Discussion: Young maternal age is not a risk factor for adverse perinatal outcomes among Indigenous women. Rather, they are having babies in disadvantaged circumstances within a system challenged to support them socially and clinically.