Research published Friday found that up to 17% of children could have symptoms found in fetal alcohol spectrum disorder, a group of lifelong conditions caused by exposure to alcohol in the womb.
FASD, also known as fetal alcohol syndrome, can cause a variety of developmental delays and physical symptoms, including a smaller head than average, poor growth, cerebral palsy, learning difficulties and autism, according to the NHS
To reach their conclusions, scientists from the University of Bristol and Cardiff University assessed the development of 13,495 children from data in Bristol's Children of the 90s study, a population-based cohort study that recruited pregnant women from the southern English city with expected delivery dates between 1991 and 1992.
The Children of the 90s study "also used a range of comprehensive measures like physical tests of growth and psychological assessments" on the children, the study's lead researcher, Cheryl McQuire from the University of Bristol, told CNN.
The UK has the fourth highest level of pre-natal alcohol use in the world, and various estimates of the disorder in Britain only "looked at a sub-type [of FASD], which is the type with facial symptoms," McQuire said.
"So we know drinking in this country is high, but we didn't know the potential number of people who had symptoms from the full FASD," she added.
FASD is also considered a relatively hidden disability because most individuals with it do not show physical features. It is also thought to be under-diagnosed in Britain.
The research found drinking was common among pregnant women; "79% reported drinking some alcohol during pregnancy, with 25% reported of drinking at binge levels," McQuire said.
While the screening measures used in the study do not equate to formal diagnoses, she said the findings show FASD is more common in the UK than first thought.
"If we fail to diagnose it then those affected individuals will continue to be affected by a lack of support and have subsequent impact on them and wider service," Raja Mukherjee, a doctor who contributed to the report and runs a diagnostic clinic for FASD, said in a statement. "These results can be the first step in helping us in the UK to realise it is no longer a condition we can ignore."
The charity British Pregnancy Advisory Service disputed the study's findings, arguing only 223 of the 13,495 people studied had full data sets, the charity said in a press release
It also warned
that the findings
could cause "undue panic, particularly as many pregnancies are unplanned, and paves the way for unwarranted and inappropriate interventions" like abortion.
Some researchers praised the study, but others questioned its use as a guide to how common the condition is in the UK.
"I would consider this research to be of high quality from a recognized authoritative source," said Christopher Steer, of the Royal College of Paediatrics and Child Health. "The figure of 17% is certainly strikingly high, well above previous indirect indications pointing to levels of between 2% and 5%."
"This research provides some potentially very useful information relating to FASD, but I really don't think it tells us anything very helpful about how common these conditions are in the UK," said Kevin McConway, emeritus professor of applied statistics at the Open University in London.
"The researchers used a screening tool that they had developed, which classified between 6% and 17% of the 13,500 children in their study as having symptoms of FASD, depending on which exact method they used," he explained.
McQuire said the researchers did not want to cause anxiety to pregnant women but were calling for follow-up studies to further clarify the current number of people in the UK with FASD.
She also said the best "possible advice" is issued by the UK's chief medical officers, which states that women who are pregnant or think they could become pregnant should not drink alcohol at all, to keep risks to the baby to a minimum.
It also advises
that the risk of harm to the baby is "likely to be low if a women has drunk only small amounts of alcohol before she knew she was pregnant or during pregnancy."