Effect of maternal methadone addiction on offspring in rats.

Female rats were addicted to methadone via small dosages in their drinking water. The addicted animals were impregnated, and continued to receive the drug during pregnancy and lactation. Offspring were examined at birth and at age 21 days. Compared to controls whose mothers did not receive the drug, pups of addicted mothers at birth had significantly lower weight, brain weight and brain protein; litter size, brain DNA and brain acetylcholinesterase activity were not significantly different between the two groups. At age 21, pups of addicted mothers had significantly lower brain protein and brain acetylcholinesterase than did controls; body weight and brain DNA were not significantly different.