Women who smoke during pregnancy are endangering themselves and their baby, NHS England has warned, as figures show more than one in 10 continue to use cigarettes.

The trend in pregnant women and the stubbornly higher rates of smoking among the least affluent groups in society trouble experts, even though the latest data shows the overall smoking rate is at an all-time low.

There has been a big reduction in the overall smoking rate to 14.4% last year, from 19.8% in 2011. There are now 5.9 million adult smokers, down from 7.7 million, which is a drop of 1.8 million over seven years.

But, according to NHS England, more than 61,000 pregnant women were still smoking last year at the time they gave birth. In Blackpool, Corby, Durham, Mansfield and a number of other areas, one in five pregnant women were smokers. The rate was lowest in the London region, with fewer than one in 20 smoking.

“Having a baby in this country is now safer than ever but smoking while carrying a baby puts both parent and child at avoidable and potentially deadly risk,” said Prof Jacqueline Dunkley-Bent, chief midwifery officer for England. “No woman should have to experience the heartbreak of stillbirth, and quitting smoking is absolutely vital for a healthy mum and a healthy baby.”

England’s overall smoking rate is lower than that of Scotland (16.3%), Wales (15.9%) and Northern Ireland (15.5%), according to data from Public Health England (PHE) and also the Office for National Statistics. Adults aged 25 to 34 were most likely to smoke (19%) while the over-65s were least likely (8%). The latest figures for school pupils aged 11 to 15 are from 2016 and show 6% were smokers.

E-cigarette use is increasing, from 3.7% in 2014 to 6.3% of adults in 2018 saying they were users. Just over half (51.5%) said they were using them as means to quit smoking. A quarter of school pupils said they had tried e-cigarettes in 2016.

Smoking continues to take a toll of the nation’s health. There were 489,300 estimated hospital admissions attributable to smoking in 2017-18, an increase of 11% on 2007. Blackpool and Sunderland had the highest admissions. In 2017, there were 77,800 deaths attributable to smoking, which accounted for 20% of deaths in men and 12% in women.

Deborah Arnott, the chief executive of the campaigning group Ash, welcomed the overall drop in the smoking rate, but said it “hides a wide disparity across society, with around one in 20 adults smoking in Richmond upon Thames, while in deprived communities such as Blackpool it is one in five.

“Higher smoking rates are responsible for half the difference in life expectancy between rich and poor. Eradicating the difference in smoking rates is the single most important step towards ending the burning injustice that, if you’re born poor, you will die on average nine years earlier than others.”

Local authorities are responsible for services to help people quit. Ian Hudspeth, the chair of the Local Government Association’s community wellbeing board, said they had made great strides but more needed to be done.

He deplored the reduction of £700m to their funding for public health. “Our ultimate aim should be to become a smoke-free nation. We still have a long way to go,” Hudspeth said.

Duncan Selbie, the chief executive of PHE, said: “Smoking in England is in terminal decline with the lowest number of smokers ever and a smoke-free generation now in sight. Unfortunately smoking rates remain high among people on lower incomes and those experiencing mental health problems and every effort and means to support them quitting is where we need to most focus.”