Sunday, November 3, 2013
What most people don't know about drinking during pregnancy.
This week, I attended a lecture given by my friend and colleague Leila Glass, M.S., who conducts research on the impact of prenatal exposure to alcohol on childhood development, specifically intellectual ability and learning.
In this talk, the-future-Dr. Glass reviewed the history of research on the impact of alcohol consumption on fetal development. For example, I was fascinated to learn that prenatal consumption of alcohol has been a public health concern since the ancient Roman Empire. Fetal Alcohol Syndrome (FAS), was not recognized as a medical diagnosis until 1973. Since then, brilliant teams of psychologists and physicians have dedicated their careers to understanding how prenatal exposure to alcohol affects a child's development. This week, I will present one piece of this research that I found particularly striking. Bear with me now, it's an oldie but a goodie.
In 1997, Dr. Sarah Mattson, a psychologist at San Diego State University's Center for Behavioral Teratology published a study with her colleagues on the intellectual functioning of children exposed to alcohol in utero. In the general public, children with FAS are recognized by a cluster of specific facial features including a low nasal bridge, a smooth philtrum, and a smaller head circumference. In addition to some of these distinct facial features, children with FAS also have low prenatal and infant birth growth, as well as damage to the central nervous system. This damage may be structural (small head circumference) or functional (intellectual disability, learning disorders). Until Dr. Mattson and her colleagues published their study in 1997, many professionals assumed that children with the facial features associated with FAS were more severely affected, while youth with prenatal exposure to alcohol who did not show the associated facial features had fewer, or even no, intellectual impairments.
Dr. Mattson and her colleagues conducted a study of 47 children who were exposed prenatally to alcohol on a daily basis. Some of these children showed the facial features necessary for the diagnosis of FAS, while some did not (PEA). These children were compared with a group of children (matched for age and gender) who were not exposed to any teratogens prenatally (NC). All children completed a series of assessments for their general intellectual ability (IQ), including vocabulary, processing speed, working memory, spatial reasoning and other domains of ability. Their over-arching research question was:
Do children who were exposed to prenatal alcohol have cognitive impairments in the absence of facial dysmorphology?
They found that children who were prenatally exposed to alcohol performed more poorly on every domain of intellectual functioning compared with the control children. More importantly, there were no differences, among the prenatally exposed children, between those who did and did not show the facial features associated with FAS. This was true for overall intellectual ability, as well as almost all sub-domains of intellectual functioning. Among the youngest children in the study, children prenatally exposed to alcohol without the FAS facial features outperformed their FAS peers in word comprehension, however this was not consistent in the older groups of children. Among these older children, prenatally exposed youth without the facial features outperformed their FAS peers in some verbal reasoning tests, however still underperformed compared with their non-exposed peers. What is also important to learn from this study is that the overall intellectual functioning (IQ) of children with prenatal exposure, with and without the associated facial features was at least one standard deviation below the average child’s. This means that these children are more likely to struggle with reading, writing, paying attention, and learning throughout their lives.
The good news? All of this is easily prevented by not drinking during pregnancy. Approximately, 12% of women drink throughout their pregnancy in the United States, and the best predictor of a child having a fetal alcohol spectrum disorder is an older sibling with one. This means that women who drink during one pregnancy are more likely to drink during other pregnancies. Obviously these data are limited because they were conducted with children who were exposed to alcohol on a daily basis in-utero. There are less clear data on what the effects of alcohol are when you compare children who were exposed to no alcohol versus very little alcohol during pregnancy. Biologically, my expectation is that there must be some effect, but they are more subtle. Alcohol easily crosses the placenta, which means that there is a 1:1 ratio between the alcohol a mother consumes and the alcohol the infant receives. If a pregnant mother drinks one 12-ounce beer, the peanut-sized fetus is essentially floating in the same amount of beer. Babies are resilient, but it’s hard to believe this would not affect the development of their liver and brain.
Other good news? The effects of fetal alcohol exposure can be effectively managed. In the past few decades, our understanding of the behavioral and cognitive profiles of children with fetal alcohol spectrum disorders has dramatically improved. Most importantly, people like Dr. Mattson, Ms. Glass and their colleagues have contributed to our understanding the differences between ADHD, Autism Spectrum Disorder, Oppositional Defiant Disorder, and Fetal Alcohol Spectrum Disorders. For example, if you have a child, student, or patient with intellectual impairments related to prenatal exposure to substances, there has been a very helpful toolkit developed to help build a safe and educational environment (http://www.dotolearn.com/disabilities/FASDtoolbox/index.htm).
The biggest barrier to implementing these very promising interventions, is that many mothers fail to mention or misrepresent their use of alcohol during their pregnancy under the belief that alcohol may not have anything to do with attention difficulties or behavioral problems that emerge during childhood. This means that more children are misdiagnosed with ADHD and Autism, or are not comprehensively assessed for an FASD due to the provided developmental history. Ultimately, this just means that the child's difficulties are less effectively treated and unnecessarily prolonged.
It goes without saying that, yes, there are very successful people who were exposed to small to moderate amounts of alcohol in-utero who grow up to be high-functioning members of society, but there's no way of knowing how much better that person could have done without that exposure. Not every person who drinks during their pregnancy will have a child with intellectual difficulties, but some will and we don't really know how much alcohol results in these effects. So, the only question is: do you want it to be yours?
Mattson, S. N., Riley, E. P., Gramling, L., Delis, D. C., & Jones, K. L. (1997). Heavy prenatal alcohol exposure with or without physical features of fetal alcohol syndrome leads to IQ deficits. The Journal of pediatrics, 131(5), 718-721.
Posted by Kate Ryan at 3:14:00 PM