Pediatrics Journal has published a report from medics at the University of Nottingham which found that stillbirths were 23 per cent more common and birth defects 13 per cent more common in women who lived or worked with smokers.
Professor Jo Leonardi-Bee, one of the report's authors, told Reuters Health that women need to be 'protected' from passive exposure to smoke before conception and through pregnancy.
She added that although the increased risks were not massive, they were 'a lot larger in magnitude than one would anticipate if we believe that passive smoke only has one percent of the effect of active smoking.'
Prof Leonardi-Bee and her colleagues at Nottingham examined data from 19 existing studies in their research.
They found the rates of miscarriage and newborn death were similar, whether or not women were exposed to secondhand smoke, and in individual cases there was no single birth defect linked to secondhand smoke - the increased risk was only evident when all the data was pooled.
None of the women whose data was examined smoked while pregnant, but they had all breathed in second-hand smoke from colleagues or family members. Fathers proved to be the primary source of second-hand smoke in half of the analysed findings.
Medical experts responded saying the research confirmed what many doctors have always assumed about passive smoke exposure, even though the findings did not prove that tobacco smoke causes birth defects or stillbirths. They also questioned, that if it did, was this down to the mum inhaling the smoke or the effects of smoking on the sperm quality of the male?
Stephen Grant from Magee-Womens Research Institute in Pittsburgh, Pennsylvania, who wasn't involved in the study, told Reuters Health he was 'intrigued by the association between secondhand smoke and birth defects'.
'What we have here is that it's possible all the chemicals in tobacco smoke could have some effect on development,' he said.
What do you think about this story?
Do you go out of your way to avoid passive smoking? Or has it not crossed your mind?
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