A bun in the oven with a drink in hand

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A team of researchers, including New Zealanders and an Australian, have looked at how many women reportedly drink during pregnancy. Looking at the UK, Ireland, Australia and New Zealand, the authors found drinking while pregnant was still very common in all four countries - regardless of social standing - and those who also smoked while expecting were significantly more likely to also be drinkers.

Journal/conference: BMJ Open

Organisation/s: The University of Adelaide, University of Auckland, Liggins Institute, University of Cambridge, UK

Media Release

From BMJ

Drinking alcohol while pregnant is common in UK, Ireland, and Australasia

Evident across all social strata but expectant mums significantly more likely to drink if they smoke

Drinking alcohol while pregnant is common, ranging from 20% to 80% among those questioned in the UK, Ireland, Australia and New Zealand, reveals a study of almost 18,000 women published in the online journal BMJ Open.

Women across all social strata drank during pregnancy, the findings showed. But expectant mums were significantly more likely to be drinkers if they were also smokers.

The researchers base their findings on an analysis of data from three studies: The Growing up in Ireland (GUI) study; the Screening for Pregnancy Endpoints (SCOPE) study; and the Pregnancy Risk Assessment Monitoring System (PRAMS).

The studies variously assessed the amount and type of alcohol drunk before and during pregnancy and involved 17,244 women who delivered live babies in the UK, Ireland, Australia and New Zealand.

The researchers mined the content to gauge the prevalence of, and the factors associated with, drinking alcohol during pregnancy.

Their analysis indicated a high prevalence of drinking, including binge drinking, among mums to be. The prevalence of drinking alcohol ranged from 20% to 80% in Ireland, and from 40% to 80% in the UK, Australia, and New Zealand.

Ireland emerged as the country with the highest rates of drinking, both before (90%) and during (82%) pregnancy, and of binge drinking, before (59%) and during (45%) pregnancy, based on estimates from the SCOPE study. But the exact prevalence could be far lower than that as estimates of drinking during pregnancy from the PRAMS and GUI studies were substantially lower (20-46%), with only 3% of women reporting binge drinking in PRAMS, caution the researchers.

The amount of alcohol drunk varied across the three studies. Between 15% and 70% of the women said that they had drunk 1-2 units a week during the first three months (trimester) of their pregnancy. But the number of reported units dropped substantially in all countries between the first and second trimester, as did binge drinking.

The findings indicated that the prevalence of drinking while pregnant was generally evident across all social strata, but several factors were associated with a heightened or lowered risk of alcohol consumption.

Compared with white women, those of other ethnicities were less likely to drink alcohol while pregnant, while younger women (30-39) were also less likely to do so than older women.

A higher level of education, having other children, and being overweight/obese were also associated with a lower risk of drinking while pregnant.

But the strongest and most consistent predictor of a heightened risk of drinking alcohol during pregnancy across all three studies was smoking. Smokers were 17-50% more likely to drink while pregnant.

The researchers point out that most clinical and government guidelines advise women to stop drinking during pregnancy.

But they write: "Alcohol use during pregnancy is highly prevalent, and evidence from this cross-cohort and cross-country comparison shows that gestational alcohol exposure may occur in over 75% of pregnancies in the UK and Ireland."

However, most of these women consumed alcohol at very low levels and the number of pregnant women who drank heavily in the three studies was small, they say.Nevertheless, given that the risks of light drinking are not fully known, the most sensible option is not to drink alcohol during pregnancy, they add.

"Since most women who consume alcohol do so at lower levels where the offspring growth and development effects are less well understood [than at  higher levels], the widespread consumption of even low levels of alcohol during pregnancy is a significant public health concern," they conclude.

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Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Professor Lesley McCowan, Head of Department, Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland

The New Zealand data included in the paper is from the SCOPE study. This involved detailed data collection about  from approximately 2000 Auckland women in their first ongoing pregnancies who were recruited between 2004 and 2007. 

Detailed information was collected from the women about alcohol use before and during pregnancy. 23% of participants reported that they were alcohol-free when they became pregnant.

Of the 53% (1063) women who reported that they drank any alcohol in the first trimester 917(86%) stopped drinking by 6 weeks of pregnancy. Stopping drinking is likely to have corresponded with having a positive pregnancy test. So the large majority of these Auckland women are likely to have stopped drinking as soon as pregnancy was diagnosed.

12% of women reported that they were still drinking alcohol when seen by the SCOPE research team at 20 weeks of pregnancy and 95% of these women were only having 1 to 2 units of alcohol weekly at this time.

Women who were single and those who smoked cigarettes were more likely to  drink during pregnancy.

As there is no known safe level of alcohol use in pregnancy the best advice is not to drink alcohol in pregnancy.

Last updated: 03 Nov 2016 4:03pm

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