Maternal ethnicity and stillbirth in Victoria from 2000 to 2011.

Background: Maternal ethnicity is an emerging risk factor for stillbirth. In this study we aimed to explore associations between maternal country of birth and the risk of stillbirth among women giving birth in Victoria. Method(s): A retrospective cohort study of routinely collected perinatal data for Victoria from 2000 to 2011. The rates of stillbirth >24 weeks (excluding TOPs and known congenital abnormalities) were determined by gestational week and maternal country of birth. Result(s): The rate of stillbirth was higher in South Asian (SA) and lower in South-East-East Asian (SE-EA) women compared to Australian (Aus) born women. Compared to Aus women, the relative risk of stillbirth among SA women increased with increasing gestation. After adjustment with known risk factors for stillbirth, SA women were 50% (95%CI 1.2-1.9) more likely to have a stillbirth and SE-EA women were almost 40% (95%CI 0.5-0.8) less likely to have a stillbirth compared to Aus women. The increased rate of stillbirth in SA women was entirely explained by undetected small for gestational age (SGA) babies. In those SA pregnancies there was an 11 fold increased risk of stillbirth (95%CI 9.6-12.9). In SA pregnancies where SGA was detected or there was not SGA the risk of stillbirth was similar to Aus women (OR 1.15 [95%CI 0.91-1.46]). Conclusion(s): Our findings suggests that improvements in the detection of small for gestational babies will likely have a large impact in the reduction of stillbirth in SA women.