Impact of smoking on future rates of stillbirth, neonatal and infant mortality and poor birth outcomes in England - Lucy Lyus, Policy and Research Manager, The Lullaby Trust

The risks of miscarriage and stillbirth are significantly increased, and babies born to smoking mothers are more likely to be born prematurely or too small, and to die in the first year of life.1 The most recent data show that around 11% of women in England smoke at the time of giving birth;2 a figure that has declined over the last decade but stagnated in recent years. [...] These were calculated by estimating the risk of each outcome in smokers and non-smokers using published estimates of the relative risk (RR) or odds ratio (OR; considered here to be equivalent to RR) of smoking on each outcome, the percentage of women smoking in pregnancy (as per the most recent rate reported in the SATOD dataset), and the proportion of each outcome, using the equation below. [...] The numbers of deliveries were predicted using projections of live birth data published by ONS.15 As the number of deliveries in NHS establishments reported in the SATOD dataset is consistently on average 95% of the number of total live births in England, this proportion was assumed to remain constant from 2017/18 to 2025/26 in order to estimate the number of future deliveries. [...] The main outcome of interest was the estimated number of stillbirths, neonatal deaths, preterm and low birthweight births, and sudden infant deaths that could be prevented in the future by reducing smoking to the target rate of 6% by 2022 compared to a) no change from the current rate of smoking in pregnancy and b) the current rate of decline. [...] DISCUSSION Using current data on smoking rates in pregnancy and the numbers of adverse outcomes related to smoking, it has been possible to estimate a range of the numbers of babies’ lives that could be saved or improved in England by reducing smoking to the target of 6% by the end of 2022.