New insight has been obtained regarding how alcohol during pregnancy might affect fetal development, according to research performed at the Medical College of Georgia Schools of Medicine and Graduate Studies, funded by the March of Dimes.
Fetal alcohol syndrome (FAS) according to the Centers for Disease Control and Prevention, affects 1 in 1,000 babies. Pregnant and sexually active women who are not using effective birth control are recommended to refrain from drinking. Most notably, babies who are the victims of this deases have classic facial malformations, including a flat and high upper lip, small eye openings, and a short nose. These facial clues could provide insight into the mechanism of this process, as well as how much alcohol imposed at what point in development might cause these changes.
Dr. Erhard Bieberich, biochemist in the Medical College of Georgia Schools of Medicine and Graduate Studies, has focused work on the mechanism that cause problems for children with FAS. Strong evidence has shown that, in just the first few weeks of fetal development, usually a period before a woman knows that she is pregnant at all, a few glasses of wine in an hour could increase cell death. Death of cells that might further develop to form the face, brain, or spinal cord could lead to developmental problems in these areas. “It’s well known that when you drink, you get a buzz. But a couple of hours later, that initial impact, at least, is gone,” states Bieberich. “But, your fetus may have experienced irreversible damage.”
In development, there is always a set of cells that die once they have served their purpose, and a set of cells that move on to form other types of cells. “There is always a very delicate balance between newly formed cells and dying cells,” says Bieberich. “It’s a very active period of that balance, because usually you develop a surplus of tissue then later melt it back down to acquire a specific shape.” The classic example of this phenomenon is the absense of webbed fingers in newborns, while the fetus maintains skin between the fingers for some time. “The digits form because the inter-digital tissue dies. If it did not die, we would have paddles instead of hands with fingers,” Bieberich says.
According to the team, damage may result from the accelerated death of neural crest cells, which help form various types of connective tissue, including bone, cartilage, and parts of the cardiovascular system. At the same time, neural tube cells form the brain and spinal cord. This means that the visible damage shown in facial abnormalities may be a signal that future problems could be present in learning, memory, vision, hearing, or other areas. The cell death can result from disruption of the metabolism of the lipids that help control the initially undifferentiated cells, due to alcohol.
The team compares cell loss in mice following various levels of alcohol consumption to the usual birth and death of cells in normal development. The focus lies in the neural crest cells, which among their other functions form the upper part of the skull. Some of these cells will remain in the brain, and are often controlled by the same factors as the neural tube cells, which might lead to the cognitive and memory problems. While this type of damage may be difficult to identify in mice of this age, it has been shown that damage to the neural crest gene can cause problems in both skull and brain development.
These measurements will help women understand the true risks of alcohol consumption during pregnancy, and help develop a method to reduce the damage. Dr. Bierberich hopes for better education: “You have to make people aware of the science behind the risk,” he says. “We are not saying that every pregnant woman who drinks three or four glasses of wine in a short period will have a baby with birth defects, but it elevates the risk.”
For more information about the Medical College of Georgia and the Bieberich Group, please see http://www.mcg.edu/.
Written by Anna Sophia McKenney