A recent research study has found that women who drink heavily in the first three months of pregnancy or even before they know they are pregnant are more likely to have premature babies. The risk continued even if the women stopped their heavy drinking after the first trimester.

The study found that women who drink moderate or high amounts of alcohol in the first trimester are "significantly more likely to deliver a pre-term infant than women who abstain from alcohol". 60g and 70g of alcohol per week constitutes moderate alcohol consumption while heavy drinking was defined as more than 68g per week.

The BJOG study was conducted by researchers from the Telethon Institute for Child Health Research at the University of Western Australia and the National Perinatal Epidemiology Unit at the University of Oxford on 4719 Australian women who gave birth between 1995 and 1997. The researchers studied the women’s alcohol consumption in terms of quantity consumed, frequency, as well as what they drank.

Although the results were not statistically different but the experts found a correlation between heavy drinking in the first trimester and premature birth with the risks becoming almost 80 % higher for women who were heavy drinkers in the first three months and then stopped. The researchers found no evidence of increased risk in women who drank small quantities however they said it was possible that the results were a "statistical quirk".

There are some experts who argue that limited alcohol consumption during pregnancy is unlikely to harm the child  though the government recommends that women trying to conceive or those who are pregnant should ideally avoid alcohol altogether. Those who chose to drink while pregnant should ensure that they do not consume more than one or two units of alcohol per week. 

The latest study shows a link between moderate to heavy drinking particularly in the first trimester. The results were the worst in the cases where the women drank heavily in the first trimester and then stopped altogether for the remainder of the pregnancy term.

The researchers feel this could be due to the fact that the sudden cessation of alcohol drinking might provoke inflammation which could harm the developing fetus in some way, although this idea was not tested during the study.

Dr Colleen O'Leary, from the University of Western Australia, who led the study, said, "The risk of pre-term birth is highest for women who drink heavily or at binge levels.

"Women should be advised that during pregnancy, drinking alcohol above low levels increases the risk to the baby and that the safest choice is not to drink alcohol during pregnancy."

The editor of the British Journal of Obstetrics and Gynaecology, Professor Phillip Steer said, "When you consider the number of pregnancies which are not planned, it is quite possible that by the time a woman realizes she is pregnant, it is too late and the damage has been done."

Taking a different side Professor Andrew Shennan, representing baby charity Tommy's said, "It is still possible that, given the relatively small number of women involved, this finding could be a statistical quirk. More research needs to be done to ascertain the true extent of the risk posed by drinking alcohol during pregnancy.”

He added that, "This is a controversial area with many conflicting results and recommendations about what is deemed a 'safe' level of alcohol consumption."

Summing it up O'Leary said, "Women should be advised that during pregnancy, drinking alcohol above low levels increases the risk to the baby and that the safest choice is not to drink alcohol during pregnancy. If pregnant women cannot stop or reduce their drinking, they should seek medical advice."  (Additional Reporting by Harkiran)