Prenatal Alcohol Exposure Can Alter the Brain’s Developing Pain Regulatory System
Tim F. Oberlander, corresponding author of the study and a professor in the Division of Developmental Pediatrics at the BC Children's Hospital, the Child and Family Research Institute (CFRI), and the University of British Columbia, said that he and his colleagues have been studying reactions to acute pain and stress regulation in newborns of mothers who took SSRI antidepressants such as Prozac during pregnancy. Another researcher, Sandra Jacobson, a professor in the Department of Psychiatry and Behavioral Neurosciences at Wayne State University, and her colleagues were also studying stress regulation and development in children who were neonatally exposed to alcohol.
Because SSRI antidepressants and alcohol both alter serotonin, which either blunts or dampens pain pathways in the brain, the researchers wanted to collaborate to examine how prenatal alcohol exposure affects pain-related responses in newborns.
Teams from both laboratories worked at the University of Cape Town, South Africa, recruiting mothers during their third trimester of pregnancy. During the first few days of life, 28 newborns were examined. Half had been heavily exposed to alcohol during pregnancy, and half were exposed to light drinking or no drinking. The researchers collected biobehavioral markers (heart rate, facial actions, salivary cortisol, and more) at three different times when blood was collected through a heel lance, which is acutely painful. The newborns were also assessed on an abbreviated Brazelton Neonatal Behavioral Assessment Scale.
Oberlander said that alcohol-exposed newborns had blunted or dampened responses to the heel lance compared to newborns with little or no alcohol exposure. The stress hormone cortisol decreased in alcohol-exposed infants and remained almost unchanged in non-exposed infants. Looking at behavioral responses, they found no differences between the two groups with regard to facial responses, but infants who were exposed to alcohol during pregnancy were less aroused according to the Brazelton Neonatal Behavioral Assessment Scale.
The blunted response to pain suggests that alcohol affects the infant’s developing pain regulatory system. Previous studies by Jacobson and others have shown that prenatal alcohol exposure can affect an infant’s reactions for up to one year.
Oberlander said that in summary, their findings show that prenatal alcohol exposure alters important areas of brain function in newborns. Altered stress regulation can increase the risk of mental and physical health problems later in life.
Source: Alcoholism: Clinical & Experimental Research, Prenatal alcohol exposure can alter the brain's developing pain regulatory system, January 27, 2010