The massive increase comes despite it being harder for women to quit as their systems absorb nicotine much quicker than men, making it harder for them to give up.

Latest figures show that the number of mums-to-be that have stopped smoking more than doubled with an increase of 230 per cent.

Health bosses say that more and more supportive husbands and partners are also quitting for the sake of their new children.

Judith Rees, pregnancy advisor for the North Tees and Hartlepool Stop Smoking Service, said: "We're delighted with the progress made by the team and pregnant mums of Hartlepool.

"We recognise it is difficult to stop smoking in pregnancy and that women metabolize nicotine 15 per cent faster than men, and during pregnancy up to 60 per cent faster so it's no surprise it's difficult for them.

"Hence the reason we're here to help them stop.

"Lots of mums are also unaware that they can use nicotine replacement therapy in pregnancy to help them stop – and it's free."

The stop smoking service provided by North Tees and Hartlepool NHS Foundation Trust offers pregnant smokers and their families a home consultation to discuss what support or nicotine replacement therapy will work best for them.

They can then attend one of the drop-in centres in Hartlepool or Stockton for their treatment.

Peter Kelly, executive director for Public Health for NHS Hartlepool urged every pregnant smoker to quit for the sake of their unborn baby.

He said: "For a pregnant woman who smokes this is the ideal opportunity to seek professional support to give up now.

"It will yield short and long term benefits for mother and child and will of course bring a financial windfall when money spent on cigarettes can be used to support the new child."

Carole Johnson, head of health improvement for NHS Hartlepool and chair of the North of Tees Smoking in Pregnancy steering group, said it is great news: "I believe this is due to the fantastic partnership working between health professionals offering a co-ordinated approach, resulting in pregnant smokers feeling encouraged and supported to quit without feeling judged or pressured.

"It is early days to get complacent and we still have a long way to go.

"But we believe we are on the right track with the help we are offering."

To find your nearest NHS Stop Smoking Service, call (01642) 635650.