WEEK 15 IS SAFE LIMIT; Quit before it hurts the baby QUIT FOR BABY'S SAKE.
The research, published on the British Medical Journal website, coincides with the Gazette's Quit For Baby's Sake campaign which is urging all mums-to-be to stub out the habit.
One in three pregnant women on Teesside are still smoking at birth but the research suggests women who do not quit by 15 weeks, are three times more likely to give birth prematurely and twice as likely to have small babies compared to women who have stopped smoking.
While it is well established that smoking in pregnancy increases the risk of miscarriage, ectopic pregnancy, premature birth, small babies, stillbirth and neonatal death, the researchers say no other study has yet determined whether stopping smoking in early pregnancy reduces the risks of small babies and premature births.
The authors surveyed more than 2,500 pregnant women who were divided into three groups: non smoker, stopped smoker and current smoker. The "stopped smoker" group all gave up before week 15.
The results show that there were no differences between the rates of premature birth between stopped smokers and non-smokers, whereas current smokers had much higher risk. Similar results were revealed for expected baby size.
Another finding was women who stopped smoking were not more stressed than those who still smoked. The research also showed smokers were more likely to be single mums, less well educated, unemployed, overweight or underweight.