Tackling smoking during pregnancy may help to reduce the socioeconomic inequalities in stillbirths and infant deaths by as much as 30-40%, according to new research published on bmj.com today.
Smoking during pregnancy has been clearly linked to stillbirth and infant deaths and smoking rates during pregnancy vary markedly with socioeconomic position. So a team of researchers set out to measure the contribution that smoking during pregnancy has on the social inequalities gap in stillbirths and infant deaths.
They studied the records of 529,317 live singleton births and 2,699 stillbirths delivered at 24-44 weeks' gestation in Scotland from 1994 to 2003.
Information on smoking during the pregnancy was identified and a deprivation score was assigned using postcode data from the 2001 population census.
The most deprived mothers tended to be younger and to be more likely to smoke and to 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 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.
Women in the most deprived category were three times more likely to smoke during pregnancy than were those in the least deprived category. Smoking during pregnancy accounted for 38% of the inequality in stillbirths and 31% of the inequality in infant deaths.
The authors conclude that both 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 to reduce the socioeconomic inequalities in stillbirths and infant deaths perhaps by as much as 30-40%.
However, they stress that action on smoking on its own is unlikely to be sufficient and other measures to improve the social circumstances, social support, and health of mothers and infants are also needed.