A new study of over 17,000 women across UK, Ireland, Australia and New Zealand has found that alcohol consumption by pregnant women is common in these countries and while women across all social strata drank alcohol during pregnancy, those who were smokers were significantly more likely to be drinkers.
The study published in journal BMK Open, is based on findings on 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.
For the latest research, scientists mined the content to gauge the prevalence of, and the factors associated with, drinking alcohol during pregnancy. They found that there is high prevalence of drinking, including binge drinking, among mums to be.
In UK, Australia and New Zealand the prevalence of drinking ranged from 40 to 80 per cent, while in Ireland it ranged from 20 to 80 per cent.
Based on the estimates from SCOPE study, Ireland emerged as the country with the highest rates of drinking, both before (90 per cent) and during (82 per cent) pregnancy, and of binge drinking, before (59 per cent) and during (45 per cent) pregnancy.
However, based on estimates from PRAMS and GUI studies, researchers warn that exact prevalence could be far lower than that as estimates. Researchers found estimates from PRAMS and GUI studies were substantially lower (20-46 per cent), with only 3 per cent of women reporting binge drinking in PRAMS.
The researchers also examined the amount of alcohol being consumed across the three studies. They found that between 15 per cent and 70 per cent of the women, drank 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.
As far as ethnicity based variation was concerned, 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.
Education also mattered and the researchers found that a higher level of education, having other children, and being overweight/obese were also associated with a lower risk of drinking while pregnant.
Smoking turned out to be one of the strongest and most consistent predictor of a heightened risk of drinking alcohol during pregnancy across all three studies. Smokers were 17-50 per cent 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 per cent 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.