A team of researchers investigated whether recent smoking bans in Belgium were followed by changes in preterm delivery.
Smoke-free legislation was implemented in the country in three phases (firstly workplaces, then restaurants, then bars that serve food) over four years.
The researchers found reductions in the risk of preterm birth after the introduction of each phase of the smoking ban.
Louise Silverton, RCM director for midwifery, said: ‘There is no doubt because it is supported by a large body of evidence, of the negative impact of smoking on the pregnant woman and her developing child and of the effects of second-hand smoke.
‘This research is encouraging but we should also be aware that many pregnant women are still exposed to second-hand smoke in domestic situations. We would hope that smokers would be considerate and refrain from smoking when pregnant women are in their immediate vicinity.
‘It is also important that when the baby is born that it spends as much time as possible - ideally all the time - in a smoke-free environment.’
The team was lead by Dr Tim Nawrot from Hasselt University in Belgium.
The researchers analysed 606,877 live, single-born babies delivered at 24-44 weeks of gestation in Flanders from 2002 to 2011.
The results show a reduction in the risk of preterm births of 3.13% on 1 January 2007 (ban on smoking in restaurants).
There is a further reduction in the risk of 2.65% after 1 January 2010 (ban on smoking in bars serving food).
The authors state: ‘Our study shows a consistent pattern of reduction in the risk of preterm delivery with successive population interventions to restrict smoking.
‘It supports the notion that smoking bans have public health benefits even from early life. More and more countries in Europe are adopting stricter legislation on smoking in public places.
‘These results underscore the public health benefit of smoking ban policies.’
To read the paper, which is published on the BMJ website, please click here