· 10.2 per cent of pregnant women were known to be smokers at the time of delivery. This compares to 10.8 per cent for the most recent quarter (quarter 4, 2015/16) and 10.7 per cent for the same quarter last year.
· The proportion of pregnant women known to be smokers at the time of delivery has been below the national ambition of 11 per cent since quarter 1 in 2015/16.
· However, there are some geographical differences amongst all NHS England Regions, smoking prevalence at delivery varied from 15.6 per cent in Lancashire to 4.7 per cent in London.
· Amongst the 209 Clinical Commissioning Groups, smoking prevalence at delivery ranged from 25.5 per cent in NHS Blackpool to 2.1 per cent in NHS West London.
· 2.1 per cent of maternities1 had an unknown smoking status in quarter 1 2016/17. This compares to 2.2 per cent for the most recent quarter (quarter 4, 2015/16) and 4.5 per cent for the same quarter last year (quarter 1, 2015/16). This should be borne in mind when interpreting the proportion of pregnant women known to be smoking at the time of delivery as the unknowns are effectively treated as non-smokers in the calculation.
· From April 2017 the definition of the proportion of pregnant women known to be smokers at the time of delivery will change to exclude those with an unknown smoking status from the denominator. If this change were implemented for the current quarter then the proportion would increase to 10.4 per cent.
 The number of maternities is defined as the number of pregnant women who give birth to one or more live or stillborn babies of at least 24 weeks gestation, where the baby is delivered by either a midwife or doctor at home or in an NHS hospital (including GP units). This count should be the number of pregnant women, not the number of babies (deliveries). It does not include maternities that occur in psychiatric hospitals or private beds / hospitals.