World-first, Adelaide research finds asthmatic women who smoke while pregnant double risk of early birth Two McLaren Vale businesses gutted by fire. Anger over new elderly driving tests. New research on smoking while pregnant ASTHMATIC women who smoke and are pregnant are increasing the risks in complications for themselves and their unborn children, researchers warn. University of Adelaide researchers made the findings after comparing data over the past ten years from more than 170,000 South Australian women. Lead author Dr Nicolette Hodyl said the findings confirmed smoking and asthma could be a dangerous mix for many pregnant women. Asthma and smoking are separately linked during pregnancy to increased risk of bleeding from the birth canal before labour, urinary tract infections, premature rupture of membranes, low birth weight and preterm birth (less than 37 weeks of pregnancy)," she said. Dr Hodyl said 5.8 per cent of pregnant women who were non-asthmatic and non-smokers experienced a preterm birth while for asthmatic women, the preterm birth rate increased to 6.5 per cent and among smoking women the rate was 9.4 per cent. But for asthmatic women who also smoked, the rate of preterm birth jumped to 12.7 per cent which was more than double the normal rate. The results have been published online ahead of print in the European Respiratory Journal.