Midwives will be given carbon monoxide detectors as part of plans to reduce the number of women who smoke during pregnancy.
Figures suggest that 18.1 per cent of mums-to-be in Wakefield use cigarettes while carrying their unborn children.
Smoking rates among pregnant mums in Wakefield are the highest in the country.
Across the Mid Yorkshire NHS Hospitals Trust, which runs Pinderfields, Pontefract and Dewsbury hospitals, the figure is 20 per cent - a rate which was described as “alarming” by a trust director last week.
Although rates of smoking during pregnancy have fallen in Wakefield, the figure remains above the national rate of just under 11 per cent.
Anna Hartley, interim director of public health at Wakefield Council, said: “We are actively supporting women and their partners to give up smoking to help themselves and to give their child the best start in life.
“There has been a steady reduction is smoking in pregnancy rates over the last few years.
“Initiatives introduced include additional educational support for midwives and providing carbon monoxide detectors for them; improved information on the harmfulness of smoking in pregnancy supplied in all packs given out by midwives and the appointment of a specialist midwife to support pregnant women to quit.
Video showing difference between healthy lung and smoker’s lung revealed
“Women will also be automatically referred by their midwife to the local stop smoking service which has a base at Pinderfields Hospital and also carries out home visits.”
The use of carbon monoxide detectors follows the success of a trial programme in the north-east, where women were screened for signs of smoking at their first appointment with a midwife.
Those that showed high levels of the chemical were put in touch with support services at an early stage. Research showed that smoking rates among those taking part nearly halved.
The campaign group Action on Smoking and Health (ASH) said that while national rates appeared to be flatlining, the decline in Wakefield suggested that the area was “doing something right”.
Spokeswoman Vicky Salt said: “Smoking during pregnancy is still a leading cause of stillbirths and neo-natal deaths in the UK.
“It’s very difficult for women who’ve been smoking for 15 or 20 years to suddenly stop. Eighty per cent of smokers take up the habit before the age of 18 which means it isn’t a fully informed free choice made when they are adults. For most it’s an addiction rather than a choice.
“It’s very important also that midwives and healthcare professionals who are treating pregnant women make them aware of the damage smoking can do to the foetus and to themselves.”