Bans on smoking in public places are linked with reductions in preterm births, says a study from Belgium published in the BMJ, which introduced smoke-free bans in three steps. Each time a ban was bought in, the risk of babies being born before 37 weeks fell. There were no downward trends in the period before the bans – and other factors such as ‘flu epidemics did not seem to explain the differences either. So, good news for the public health benefits of smoking bans as premature birth is an important health risk factor.