Pregnant women who smoke should be encouraged to switch to e-cigarettes, health officials claim.

Midwives and doctors are being urged to be ‘positive’ about the devices and explain that they are probably safer than tobacco.

Patients should also be allowed to vape in hospital – and hospitals should ensure e-cigarettes are available in their shops, it was suggested.

The recommendations from the government agency Public Health England claim vaping is less than 5 per cent as dangerous as smoking.

Patients should be allowed to vape in hospital – and hospitals should ensure e-cigarettes are available in their shops, it was suggested

PHE has published a review of the evidence, which states e-cigarettes are helping tens of thousands of smokers quit.

But experts said the advice was premature, as not enough is known about the long-term risks. Recent studies linked vaping to heart disease, bronchitis, lung and bladder cancer and nicotine addiction.

Approximately 2.9million adults in the UK use e-cigarettes, while 7.6million smoke ordinary cigarettes.

Some use both if trying to wean themselves off tobacco. But PHE believes many aren’t bothering to try e-cigarettes in the mistaken belief that they are just as harmful.

Today’s review, published in The Lancet, claims too many smokers have ‘misplaced fears’ over vaping.

Around one in ten pregnant women are smokers, but this figure rises to one in four in some areas. Professor Linda Bauld, of Cancer Research UK, said: ‘If a pregnant woman is smoking and she’s struggling to stop, she shouldn’t be discouraged from using an e-cigarette.

‘Health professionals should be positive about e-cigarettes in pregnancy for smokers, but also make clear that there are no published trials.’

Pregnant women who smoke should be encouraged to switch to e-cigarettes, health officials claim

There has not been any research into whether e-cigarettes are harmful for unborn babies or pregnant women.

But Professor Bauld said the evidence so far suggested they were significantly less dangerous than ordinary cigarettes – which put mothers-to-be at a much higher risk of miscarriage, premature birth and birth defects.

Martin Dockrell, PHE’s lead on tobacco control, said it made ‘perfect sense’ for vaping to be allowed in hospital, adding: ‘There is no reason why a hospital shouldn’t designate some indoor areas where patients and visitors can vape.’

But Professor Martin McKee, of the London School of Hygiene and Tropical Medicine, pointed out that a more extensive review in the US, published two weeks ago, was much more ‘cautious’ about e-cigarettes’ long-term safety.

‘England stands out internationally in embracing these products, with experts in the rest of the world expressing much more caution,’ he said.

The PHE review looked at studies published from January 2015 to August 2017.

PHE’s Professor John Newton said it ‘reinforces the finding that vaping is a fraction of the risk of smoking, at least 95 per cent less harmful, and of negligible risk to bystanders.

‘It would be tragic if thousands of smokers who could quit with the help of an e-cigarette are being put off due to false fears about their safety.’