A new study from Perth's Telethon Institute for Child Health Research has found evidence that the amount and timing of alcohol consumption in pregnancy affects child behaviour in different ways.
The study has just been published online in the international journal Addiction.
Lead author Colleen O'Leary said the analysis was drawn from a random sample of more than 2000 mothers who completed a questionnaire three months after the baby's delivery, and were then followed up when the child was 2, 5 and 8 years of age.
"Mothers who reported what we would classify as heavy drinking in the first trimester of pregnancy were nearly three times as likely to report that their child suffered with anxiety and/or depression or somatic complaints," Ms O'Leary said.
"Those who drank moderately during that first trimester were twice as likely to report those types of behavioural issues for their child.
"Exposure to moderate or heavy levels of alcohol in late pregnancy increased the risk of aggressive types of behaviours in the child.
"This research suggests that both the timing and the intensity of alcohol exposure in the womb affect the type of behaviour problems expressed."
In this study low levels of alcohol did not increase the risk of harm to the baby. However, the evidence clearly shows that the risk to the baby increases with increasing amounts consumed.
"It should also be noted that in this study moderate exposure is classified as drinking 3-4 standard drinks per occasion- that's about two normal glasses of wine-and no more than a bottle of wine drunk over a week."
Heavy drinking included women who were drinking the equivalent of more than a bottle of wine per week. It is important that women who had consumed alcohol while pregnant are not panicked by the findings.
"Not every smoker gets lung cancer despite them being at higher risk - and in this case, not every child will be affected by prenatal exposure to alcohol. However it is important that women have this information about increased risk so that they can make informed decisions to give their child the best start to life," Ms O'Leary said.
The National Health and Medical Research Council recommend that the safest choice for women who are pregnant or planning a pregnancy is to abstain from alcohol.
Ms O'Leary said health professionals can assist by talking to women of child bearing age about their alcohol consumption and encouraging pregnant women and women planning a pregnancy to abstain from alcohol.
More information: O'Leary, Nassar, Zubrick, Kurinczuk, Stanley and Bower, Evidence of a complex association between dose, pattern and timing of prenatal alcohol exposure and child behaviour problems, Addiction, November 2009.
Source: Research Australia (news : web)
Explore further: Little evidence that binge drinking while pregnant seriously harms fetus