During the month of August, two publications delved into the decades-old debate questioning exactly how drastically a mother’s activities while pregnant affect her child in the future—specifically in terms of alcohol consumption. We asked Elizabeth Sowell, PhD, director of the Developmental Cognitive Neuroimaging Laboratory at The Saban Research Institute of Children’s Hospital Los Angeles and Professor of Pediatrics at the USC Keck School of Medicine, to share her thoughts:
Dr. Sowell, you’ve dedicated two decades to studying alcohol’s impact on brain development. How has this field evolved over the years?
Originally, a fetal alcohol syndrome diagnosis depended on identifying tell-tale markers such as malformed facial features, smaller head size, neurocognitive impairment and growth restrictions. But now, the numerous effects of prenatal alcohol exposure have been recognized as a spectrum of diagnoses among specialists —much like autism spectrum disorders. Fetal alcohol syndrome, as defined in 1973 by my friend and colleague Ken Jones, is now considered to be at the severe end of fetal alcohol spectrum disorders (FASD).
How does your most recent study influence your view on the safety of drinking during pregnancy?
Our recent study found that kids with FASD and their healthy counterparts showed significant differences in the way their brain connections developed over time —even when they performed the same on cognitive tasks. This demonstrates that prenatal alcohol exposure can alter the development of brain signaling during childhood and adolescence, long after the damaging effects of alcohol exposure in utero.
While these results demonstrate the long-lasting negative effects of prenatal alcohol exposure, the truth of the matter is, is that there is no known safe level of alcohol to drink during pregnancy. That doesn’t mean that there isn’t a safe amount, we just cannot say for certain that we know what it is.
Doctors and researchers hunting for this “safe” amount have drawn very different conclusions. Some published papers say you can drink “occasionally.” Others say drinking during the third trimester is “ok.” And many say don’t drink at all. How can you explain these disparate views?
Early on, controlled animal studies indisputably showed that alcohol consumption during pregnancy can cause birth defects. Over the last 20 or so years, non-invasive brain imaging techniques (magnetic resonance imaging), have allowed scientists to focus on alcohol’s effect on the developing human brain. Unfortunately, people are harder to study.
We need to rely on mother’s reports of their drinking during pregnancy, which may not accurately portray the quantity and pattern of their alcohol consumption. This is in part because there is a social stigma in the US about drinking during pregnancy, which may lead women who admit to drinking alcohol, to under-report actual alcohol consumption during pregnancy.
Given all of the conflicting evidence, how do you suggest women make the best decision about drinking during their pregnancy?
I would urge mothers to seriously weigh the risks of drinking during pregnancy, relative to the benefits (if any) in women’s quality of life while pregnant. Women who are trying to make sense of the scientific literature may think it’s “ok” to drink because one study showed that moderate drinking, on average, has no effect on the baby’s health. But “moderate” drinking means something different to every individual. And while “average” seems positive, it also means that there are children on either side of that line who showed symptoms of FASD.
Above all, mothers need to be educated and make their own decisions based on all available evidence.