All evidence is not created equal: New study on alcohol during pregnancy
A new study with a press release that claims "No safe amount of alcohol during pregnancy, suggest researchers" was published on Friday.
In this study, they did brain scans of "21 healthy teenage subjects and 19 subjects with prenatal alcohol exposure" (PAE). They found that people with PAE had different brain activation to touch and had reduced scores for cognitive measures. Ok, fine.
But where does their claim that "no safe amount of alcohol consumption during pregnancy" come from?
They recorded the level "maternal drinking levels of PAE participants" as either "all", "1st trimester", and "on and off". There were 5 participants with PAE whose mothers drank "on and off" during pregnancy and 1 whose mother drank during the 1st trimester. While essential for the analysis, exactly how much the mothers drank is unknown. Because these 6 participants had different brain activation and reduced cognitive scores, the researchers felt they could go on to make their sweeping claim.
This type of science is sloppy and irresponsible, not only because it is not scientifically sound, but because it creates a false narrative in non-scientific media. Take a look at the headlines describing the article:
- Daily Mail: Not even one glass of wine a week is safe during pregnancy because 'ANY amount of alcohol damages nerves in unborn babies' brains'
- Tech Times: No Amount Of Alcohol Is Safe During Pregnancy: Study
- The Health Site: Alcohol consumption during pregnancy can cause cognitive impairments in your child
Whether these results are in line with evidence on drinking during pregnancy (I have not reviewed the evidence, so I don't know) is irrelevant. This is a fabricated conclusion that will unfortunately add weight to an serious public health concern.
How do you navigate scientific findings and sort the good science from the bad?
I was able to quickly understand this study and its flaws because of my training as a scientist. Can non-scientists learn to judge scientific merit?
Thanks for sharing [@mention:366389314722672528]!
I think it's important when working in the healthcare system, especially when your job is to evaluate evidence and provide advice, that you have a good understanding of how to critically evaluate the research base. On this issue in particular, a quick Google Scholar search yielded studies with conclusions on both sides of the spectrum, including this study from Lundsburg et al. (2015) in the journal Annals of Epidemiology that concluded:
"Our results suggest low-to-moderate alcohol exposure during early and late gestation is not associated with increased risk of low birthweight, preterm delivery, intrauterine growth restriction, and most selected perinatal outcomes."
Looking at some other systematic reviews, they seem to suggest that the evidence isn't strong enough one way or another, so to be safe doctors should advise abstaining from alcohol. I feel like that is a pretty standard conclusion, and one that my doctor told me when I was pregnant. This is definitely a far cry from the authors far reaching conclusions in the article you mentioned.
I agree though, this may be hard for people with a non-academic/science background, as journal articles can be worded very jargony, and it can be hard to make sense of them. This is why I also think that journalists have some role to play in making sure the argument is balanced and fair, but I think that is a whole other discussion.....