Advice to pregnant women varies from a complete ban on alcohol to moderate drinking.
Faced with the conundrum, psychologist Janni Niclasen from the University of Copenhagen investigated and found women who drank a total of 90 units – ten bottles of white wine with an alcohol level of 12 per cent – throughout their pregnancy had better emotionally adjusted and behaved children.
However, she pointed to the correlation between middle-class mothers and light drinking.
She warned it was “important to emphasise that this is not an invitation to pregnant women to drink alcohol”.
She added: “My study shows, among other things, that the children of mothers who drank small quantities of alcohol – 90 units or more – during their pregnancies show significantly better emotional and behavioural outcomes at age seven compared to children of mothers who did not drink at all.
“At first sight this makes no sense, since alcohol during pregnancy is not seen as beneficial to child behaviour.
“But when you look at the lifestyle of the mothers, you find an explanation. Mothers who drank 90 units or more of alcohol turn out to be the most well-educated and have the healthiest lifestyle overall.
“Further, it is a question of taking account of childhood related psychological factors like attachment between mother and child in this type of study.
“This is a problem because we know that attachment is a very significant predictor for child cognitive and mental health. Therefore it should be taken into account in our statistical analysis.”
Ms Niclasen followed up on a large population study done by the Danish health and medicine authorities which gathered information about alcohol and pregnancy.
She only examined the alcohol consumption of women who drank small quantities of alcohol during pregnancy, so the results do not show the effect on children whose mothers drank heavily during pregnancy.
The population study between 1996 and 2002 involved 100,000 pregnant Danish women interviewed on three separate occasions about their consumption of alcohol, twice in pregnancy and again when their child reached six months.
When their children were seven, 37,000 women who had answered all three rounds of questions were contacted again.The aim was to screen for children’s and adolescents’ behaviour, emotions and peer relationships, but did not include psychological, socio-demographic and lifestyle factors.
Ms Niclasen warned: “It is already difficult to control for all the lifestyle factors as it is, and when, on top of that, information is lacking about psychological variables – like for instance attachment and intelligence – then you need to be careful when interpreting the result.”