TUESDAY, April 25, 2006 (HealthDay News) -- A study of rats suggests that maternal drinking during pregnancy can disrupt the circadian "day-night" rhythms of offspring.
Circadian rhythms regulate most body processes and play an important role in sleep and other mechanisms important to health.
The study found that fetal exposure to alcohol during a period equivalent to the third human trimester altered the rats' ability to synchronize their circadian rhythms to light cues. The rats were exposed to levels of alcohol that simulated heavy binge drinking by pregnant women.
"Our study demonstrated that exposure to alcohol during the third trimester, when components of the circadian system in the brain are developing, can lead to long-lasting alterations in the ability to entrain the cycles to environmental cues, like light/dark cycle," corresponding author Jennifer D. Thomas, associate professor of psychology at San Diego State University, said in a prepared statement.
"These data suggest that dysfunction of circadian systems may contribute to some of the behavioral problems in children with FASD (fetal alcohol spectrum disorders)," Thomas said.
"Human infants with FASD may suffer from sleep disorders, including a reduced amount of sleep, abnormal brain wave activity, and fragmented rapid eye movement and slow-wave sleep, which may be related in part to circadian dysregulation," she noted.
"Disruptions in circadian rhythms can also influence other behaviors, including attention and mood regulation. In fact, individuals with FASD may suffer from depression and other psychopathologies," Thomas added.
This study reinforces the message that drinking during pregnancy can cause long-lasting damage to children.
"There is currently no known safe amount of alcohol that can be consumed during pregnancy, so it is best to abstain from alcohol drinking during pregnancy," Thomas said. "We need to better understand the mechanisms of this dysfunction to determine if there are ways to mitigate the circadian dysfunction and behavioral dysregulation associated with developmental alcohol exposure," she said.
The U.S. National Institute on Alcohol Abuse and Alcoholism has more about drinking and pregnancy.