Pregnant women in the North are almost nine times more likely to smoke than those in the South.
During the same period, on average, almost 15% of women across England smoked while they were pregnant.
The North/South divide also came into effect as the same survey showed the rate of smoking-related deaths from lung cancer in Middlesbrough as 71 victims per 100,000 from 2006-08, while there were just 19 per 100,000 in Guildford.
Overall there were 207 smoking related deaths per 100,000 people aged 35 and over in England during the period 2006-08. This was down from the 216 deaths per 100,000 from 2004-06.
Director of the London Health Observatory, Dr Bobbie Jacobson, said there was a clear mix of good and bad news.
She said: “The overall picture of falling death rates is encouraging and shows what can be achieved over time through clear plans to tackle the harm from smoking. But the North/South inequalities remain a stark reminder that the biggest burden of smoking-related ill health still falls on our poorest communities.
“The significant proportion of women who reported smoking in pregnancy is a sign of our need to redouble our preventative efforts in primary and maternity care.”