Pregnant women have been urged not to play Russian Roulette with the health of their unborn child – as new figures show Barking and Dagenham has the second highest rate of smoking during pregnancy in London.

The calls come as an investigation reveals the health of hundreds of unborn children every year is at risk from their mothers smoking cigarettes.

This can lead to miscarriage, premature birth, low birth weight and other complications that disadvantage a child before it is born.

The data shows that 10.1 per cent of expectant mums - or 616 women - smoked in Barking and Dagenham from April 2013 to December 2014.

Health experts described our findings as “concerning”.

Hazel Cheeseman, director of policy at ASH (Action on Smoking and Health), said: “Giving up smoking while pregnant is one of the biggest things people can do to ensure their baby is healthy.

“If you smoke when you are pregnant the inequalities for that child begin before they are even born.

“They are at a higher risk of illness and have a greater chance of becoming a smoker in the future.”

According to ASH, up to 2,200 premature births, 5,000 miscarriages and 300 deaths in the first week after birth are caused by smoking during pregnancy every year in the UK.

We analysed the latest Department of Health data for more than 200,000 pregnancies in London from April 2013 to December 2014.

The greatest success in tackling the issue has been in the capital where the majority of boroughs now have a smoking rate among pregnant women of below 10pc compared to the England average of 11.7pc.

ASH said this was due to factors such as a high proportion of women from ethnic groups where smoking is not prevalent, becoming pregnant when older than elsewhere in the country, and increased awareness and publicity.

But figures over five years show the rates of pregnant women smoking in Barking and Dagenham have not fallen.

In 2006-07 some 10pc of mums were smoking at the time they gave birth and this rose to 11.3pc in 2007-08 and 2008-09.