5 october 2009

Smoking during pregnancy a cause of social inequality in stillbirths

Health

Cigarette smoke by Tomasz Sienicki via Wikimedia Commons
Tackling smoking during pregnancy could help plug the social inequality gap in stillbirths and infant deaths.

Tackling smoking during pregnancy may help to reduce socio-economic inequalities in stillbirths and infant deaths by as much as 30–40 per cent, according to a new Oxford University-led study published in the British Medical Journal.

Smoking during pregnancy has been clearly linked to stillbirth and infant deaths, and smoking rates during pregnancy vary markedly with socio-economic position. So a team of researchers led by Dr Ron Gray at the National Perinatal Epidemiology Unit at Oxford set out to measure the contribution that smoking during pregnancy has on the social inequality gap in stillbirths and infant deaths.

'Our study looked at data from all admissions to maternity units in Scotland between 1994 and 2003,’ says Dr Gray. ‘We found increased risk of stillbirths and infant deaths to women living in the most deprived areas of Scotland compared to those living in the most advantaged areas.’

The stillbirth rate increased from 3.8 per 1000 in the least deprived group to 5.9 per 1000 in the most deprived group. For infant deaths, the rate increased from 3.2 per 1000 in the least deprived group to 5.4 per 1000 in the most deprived group. Stillbirths were 56% more likely and infant deaths were 72% more likely in the most deprived compared with the least deprived category.

Some of the social inequality in these outcomes, perhaps 30–40 per cent, is accounted for by smoking during pregnancy.

Dr Ron Gray

‘Some of the social inequality in these outcomes, perhaps 30–40 per cent, is accounted for by smoking during pregnancy,’ explains Dr Gray.

The researchers found that women in the most deprived category were three times more likely to smoke during pregnancy than were those in the least deprived category. The most deprived mothers tended to be younger and more likely to smoke and give birth to preterm or low birth weight babies. Equally, the least deprived mothers were more likely to be older, non-smokers, and less likely to give birth to preterm or low birth weight babies.

The authors conclude that tackling smoking during pregnancy and reducing infants’ exposure to tobacco smoke in the postnatal environment may help to reduce stillbirths and infant deaths overall, and help reduce the socio-economic inequalities in stillbirths and infant deaths.

‘Tackling smoking during pregnancy will be important in reducing this inequality gap, but such action on smoking is unlikely to be enough on its own. Other initiatives to support mothers and children, such as measures to deal with poverty among socially excluded families, will be necessary as well,’ says Dr Gray.