British women drink the most during pregnancy, despite recommendations to abstain from alcohol during this time, according to a new survey of 11 European countries.

Researchers, including those from University of Oslo in Norway, studied about 7905 women, 53 per cent of whom were pregnant, and 46 per cent were new mothers (with a child up to one-year-old).

The countries included were Croatia, Finland, France, Italy, Norway, Poland, Russia, Serbia, Sweden, Switzerland and the UK.

The countries with the highest proportion of women who reported alcohol consumption during pregnancy were the UK (28.5 per cent), Russia (26.5 per cent) and Switzerland (20.9 per cent).

The women completed an anonymous online questionnaire, which was available on selected websites intended for pregnant women in the respective countries.

Researchers found on average, 16 per cent of women reported that they drank alcohol after they knew that they were pregnant.

The countries with the highest proportion of women who reported alcohol consumption during pregnancy were the UK with 28.5 per cent, Russia with 26.5 per cent and Switzerland 20.9 per cent.

The countries with the lowest proportion of women who reported alcohol consumption were Norway (4.1 per cent), Sweden (7.2 per cent) and Poland (9.7 per cent).

Women who reported alcohol consumption during pregnancy were more likely to be older, more highly educated, in employment, and had smoked before pregnancy than women who did not report this consumption, researchers said.

Of those women who said they drank alcohol during pregnancy, 39 per cent consumed at least one unit of alcohol per month.

Those who drank most frequently more than one to two units per week were in Italy (7.8 per cent of the women said they drank during pregnancy)and the UK 2.8 per cent.

Those who drank the least 1-2 units during the whole pregnancy were in Norway and Sweden (over 80 per cent of the women who said they drank during pregnancy) and France, Poland, Finland and Russia 70-80 per cent.

"Differences in pregnant women's drinking behaviour between countries can have many explanations besides variations in willingness of women to provide information about their alcohol consumption during pregnancy," said Hedvig Nordeng from the Norwegian Institute of Public Health.

"There could be differences in national guidelines or educational campaigns about drinking during pregnancy, differences in prenatal care and attitudes towards alcohol use in pregnancy, or a combination of all these factors," he said.

"We can speculate that both social and cultural factors play a role. Women's attitudes on the one hand, and national alcohol-related guidelines and policies on the other, may influence women's drinking behaviour during pregnancy," said Angela Lupattelli from the University of Oslo.

The study was published in the journal Women and Birth.