Fetal Alcohol Spectrum Disorder (FASD) refers to a constellation of disorders resulting from prenatal exposure to alcohol; the manifestations include birth defects, developmental disabilities, and neurological and behavioral problems. Prenatal alcohol exposure is the most common preventable cause of birth defects, and fetal alcohol spectrum disorders are the most commonly identifiable causes of developmental delays and intellectual disabilities. Based on the multiple studies demonstrating an association between alcohol exposure and these disorders, the American Academy of Pediatrics (AAP) has taken a firm stand against the use of alcohol during pregnancy.
A study published last month in JAMA suggests that fetal alcohol spectrum disorders may be more common than previously believed. May and colleagues conducted a cross-sectional survey of first-graders in public and private elementary schools in four communities, located in the Midwest, the Rocky Mountain area, the Southeast, and the Pacific Southwest.
The prevalence of FASD ranged from 1.1% (in the Midwest community) to 5.0%, (in the Rocky Mountain community) using a conservative estimation approach, and was as high as 3% to 10% using a less conservative estimation. Previous studies have described a lower prevalence of FASD, with a recent meta-analysis calculating a pooled prevalence in the United States of about 2%.
Given the high prevalence of FASD, the authors argue for comprehensive surveillance systems to monitor alcohol use by pregnant women and the prevalence of FASD among children. While previous studies have estimated that about 10% of women drink during pregnancy, this study did not include any information on patterns of alcohol use in the mothers.
It seems, however, that we are sending a mixed message regarding the use of alcohol during pregnancy. Women receive a wide range of recommendations, where many articles, like this one, challenge the strict recommendations of the American Academy of Pediatrics, stating that “light drinking” during pregnancy is probably safe. If you search Is It Safe To Drink Alcohol During Pregnancy?, the first hit brings you to this statement from Baby Centre UK:
It’s safest not to drink alcohol at all during pregnancy. However, if you do decide to drink while you’re pregnant, limit it to one or two units of alcohol, no more than once or twice a week, and never enough to get drunk.
Author Emily Oster, in a series of widely read articles and a book entitled Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong–and What You Really Need to Know, calls into question the recommendations made by the American Academy of Pediatrics stating that no amount of alcohol should be considered as safe to drink during any trimester of pregnancy. She argues that, while there are multiple studies to indicate that heavy drinking poses significant risks to the developing fetus, the data regarding the effects of light to moderate drinking are less clear. In the context of that uncertainty, medical professionals tell their patients that the safest option is abstinence during pregnancy. In contrast, Oster, and some professionals (especially outside of the United States), have a more benign view of alcohol during pregnancy, stating that light drinking during pregnancy is probably safe.
We know that FASD can vary in terms of severity and that heavy alcohol use is more likely to cause FASD than lighter alcohol use. But we don’t really know what constitutes safe drinking. Some doctors may say that it’s OK to have a drink of wine with dinner, but at this point we don’t have enough data to support that recommendation. Because we don’t have enough information to indicate the safety of “light” alcohol use and because alcohol is it not medically necessary or beneficial during pregnancy, we recommend that women refrain from drinking alcohol during pregnancy.
Ruta Nonacs, MD PhD
May PA, Chambers CD, Kalberg WO, et al. Prevalence of Fetal Alcohol Spectrum Disorders in 4 US Communities. JAMA. 2018 Feb 6;319(5):474-482.
Fetal Alcohol Disorders Much More Common Than Prior Estimates (Medscape – free subscription)