Perinatal health outcomes of East African immigrant populations in Victoria, Australia: a population based study

Background: Sub-Saharan African women are often treated as a single group in epidemiological studies of immigrant birth outcomes, potentially masking variations across countries. Methods: Cross-sectional population-based study of 432,567 singleton births in Victoria, Australia comparing mothers born in one of four East African countries (453 Eritreans, 1094 Ethiopians, 1,861 Somali and 1,404 Sudanese) relative to 427,755 Australian-born women was conducted using the Victorian Perinatal Data Collection. Pearson's chi-square test and logistic regression analyses were performed to investigate disparities and estimate risks of perinatal mortality and other adverse perinatal outcomes after adjustment for confounders selected a priori. Results: Compared with mothers born in Australia, East African immigrants as a group had elevated odds of perinatal mortality (ORadj1.83, 95 % CI 1.47, 2.28), small for gestational age births (SGA) (ORadj1.59 95 % CI 1.46, 1.74), very low birthweight (ORadj1.33, 95 % CI 1.11, 1.58) and very preterm birth (ORadj1.55, 95 % CI 1.27, 1.90). However, they had lower odds of preterm birth (ORadj0.86 95 % CI 0.76, 0.98) and macrosomia (ORadj0.65 95 % CI 0.51, 0.83). Individual country of birth analyses indicated significant variations, with Eritrean women having higher odds of very low birthweight (ORadj1.80, 95 % CI 1.09, 2.98), very preterm birth (ORadj 1.96, 95 % CI 1.08, 3.58), small for gestational age births (ORadj 1.52, 95 % CI 1.14, 2.03) and perinatal mortality (ORadj 2.69, 95 % CI 1.47, 4.91). Sudanese women had higher odds of low birthweight (ORadj 1.36, 95 % CI 1.10, 1.68), very low birthweight (ORadj 1.53, 95 % CI 1.13, 2.07), very preterm birth (ORadj 1.78, 95 % CI 1.26, 2.53), small for gestational age births (ORadj 2.13, 95 % CI 1.84, 2.47) and perinatal mortality (ORadj 2.10, 95 % CI 1.44, 3.07)]. Ethiopian women differed from Australian-born women only in relation to higher odds of very preterm birth, (ORadj1.70 95 % CI 1.16, 2.50), and only Somali-women had significantly lower odds of preterm birth (ORadj0.70 95 % CI 0.56, 0.88). Conclusions: Overall, East African countries of birth were associated with increased perinatal death and some adverse perinatal outcomes; suggesting the need for strategies to enhance surveillance and health care delivery for these women. Analysis by individual country of birth groups has shown women from Eritrea and Sudan are particularly at increased risk of adverse outcomes, demonstrating the importance of antenatal identification of maternal country of birth.