Researchers say up to 80% of pregnant women in the UK, Ireland, Australia, and New Zealand have had an alcoholic beverage during their pregnancies—some due to the fact that they didn't realize they were pregnant when they threw one back, the Guardian notes. But getting that "positive" sign on the pregnancy test may not need to be so worrisome for those who unknowingly indulged beforehand, per a new study in the BMJ Open journal. Per a press release, University of Bristol scientists who conducted a meta-analysis of thousands of studies say there's a "surprisingly limited" amount of evidence that shows light drinking—32 grams per week, the equivalent of four units (basically two small drinks)—has any detrimental effect on infants.
Researchers sifted through almost 5,000 abstracts from 1950 to 2016, finding 26 observational studies relevant to how light drinking may be tied to pregnancy complications, birth characteristics, and developmental delays. The findings: Consuming up to four alcoholic units weekly while pregnant was tied to an 8% higher risk of having a small baby compared with abstaining, though an Imperial College London obstetrics expert notes to the Guardian there may be "other possible explanations" for this elevated risk. A less-clear link to light drinking was a somewhat heightened risk of early birth. But an expert tells Sky News that although the findings may ease the minds of women who accidentally consumed alcohol while pregnant, "our advice as health professionals must be the safest option is to avoid alcohol" altogether. (NYC bartenders can't refuse to serve pregnant women.)