More women in the North East of England carry on smoking during their pregnancy than anywhere else in the UK, recent research has revealed.

According to data published by the NHS Information Centre covering 167,300 pregnancies, over 20% of women living in the North East were smokers when they gave birth, compared to 6.1% of mothers in the South.

The data, provided by GPs from 149 primary care trusts, revealed that smoking pregnant women in England varied from 2.8% in London, to 30.3% in Blackpool, the highest percentage of pregnant smokers in the UK.

According to data from last year, which looked into pregnant smoking in the UK as a whole, 16% of Welsh pregnant women had smoked during their pregnancy, 13% in Scotland and 15% in Northern Ireland.

Across England, 13.4% of pregnant women admitted to being a smoker at the time of giving birth.

The NHS Information Centre chief executive, Tim Straughan, said in a statement: "Smoking can cause a range of serious health problems, including lower birth weight, pre-term birth, placental complications and perinatal mortality.

"The statistics we have published today highlight stark regional variation in the proportion of women smoking at the time of giving birth. They will be of considerable interest to those responsible for promoting good health during and after pregnancy."

The number of pregnant smokers surprised midwife and antenatal teacher Janine Rudin, from Birth and Baby Network, who told The Huffington Post: "I'm really shocked by this figure. It could be due to pregnant women who live in more deprived areas, who may also be young and there may be a lack of information and understanding about how smoking can affect their unborn baby.

"It would be great to know if the levels of support regarding giving up smoking are different around the country."

Fertility expert, Emma Cannon, added to this, telling The Huffington Post: "Smoking thins the endometrium (womb lining) and in fertility terms it ages a woman by 10 years.

"There are many health problems for the baby associated with mothers who smoke; not least low birth weight and an increased risk of cot death. If the mother smokes the baby will smoke too. Mother's need support to give up smoking and non invasive methods like acupuncture could be a helpful tool to make the expectant mother feel calmer as she stops smoking."

Martin Dockrell from Action on Smoking and Health (ASH) told The Huffington Post: "Smoking in pregnancy is one of the most shocking examples of health inequalities in England. More deprived women are almost three times as likely to smoke when they become pregnant compared to better off women and they are about half as likely to quit.

"Although the numbers of women smoking has been falling over recent years the health gap has been getting wider, this is because the decline in smoking has been mostly among better off women. Any reduction in smoking in pregnancy is welcome but without some radical improvement we will not come anywhere near achieving the Government’s published ambitions.”

According to the SmokeFree charity, children exposed to cigarette smoke in the womb are times more likely to become smokers themselves when they grow up and six times more likely to develop childhood asthma than babies born to non-smokers.

Previous studies have discovered that smoking in pregnancy could increase the risk of teen obesity, as well as low birth weight and higher risks of infant death syndrome.

More serious birth defects, including deformed limbs, clubfoot, gastrointestinal and cleft lip have also been linked to smoking in pregnancy, in particular gastroschisis, a condition where parts of the stomach protrude through the skin.