One in 10 pregnant women in Gloucestershire were smokers at the time of delivery, new figures show.
It comes as the Smoking in Pregnancy Challenge Group forecast the Government's target to reduce rates of maternal smoking to 6% by 2022 will only be met in 2032. The coalition said a new strategy is needed urgently.
NHS England figures for the former NHS Gloucestershire CCG show 529 of 5,400 mothers were smokers (9.8%) at time of delivery in 2022-23.
It was above the national ambition of 6% or less.
Professor Linda Bauld, co-chair of the Smoking in Pregnancy Challenge Group, said helping more mums-to-be quit smoking spares dozens of families from losing their baby to stillbirth or miscarriage, as well as easing pressure on vital NHS services.
Nationally, 8.8% of pregnant women were smoking at time of delivery in 2022-23 – a slight fall from 9.1% the year before.
The figures also show just eight of the 106 sub-integrated care boards that submitted smoking rates met the target, most of which were in London.
Dr Clea Harmer, co-chair of the group and chief executive of the Stillbirth and Neonatal Death charity, said: "We are deeply concerned that the Government has missed their target of 6% or fewer pregnant women smoking by 2022 and isn’t on track to achieve it until the 2030s."
"The measures announced in April are an important step in the right direction, but they follow years of inaction and delay from successive Governments," Dr Harmer added.
She said the Government urgently needs to publish a comprehensive strategy to tackle smoking among mums-to-be and added it should include a levy on tobacco companies.
A Department of Health and Social Care said it is committed to reducing smoking rates, particularly among pregnant women.
A spokesperson added the department has a new financial incentive scheme, in the form of vouchers, which will be offered to all pregnant women who smoke by the end of 2024.
"Women who receive incentives are more than twice as likely to quit as those who do not and schemes like this help women to engage with stop smoking support and remain smokefree throughout their pregnancy."
They added a smokefree treatment pathway will be introduced for pregnant women by March 2024 where women who smoke will be referred for specialist support.