Canadian scientists have found from animal experiments, that just one single exposure to methamphetamine during fetal development induces DNA damage in the brain and increases the risk of long-term abnormal motor development.
Lead investigator Dr. Peter G. Wells, in a University of Toronto press statement, says that they had already known that meth abuse during pregnancy is associated with low birth weight, cleft palates and other malformations but this, he says, is the first research demonstrating that even a single exposure can cause long-term damage.
In their paper Wells' team explain that as methamphetamine use is increasing in women of childbearing age, it emphasizes the need for a better understanding of the consequences.
In their study the researchers injected pregnant mice with one of two doses of methamphetamine on day 14 of pregnancy, the embryonic period, and on day 17, the fetal period.
The investigators say that the higher dose results in levels similar to those seen in premature infants born to methamphetamine-abusing mothers.
The authors say that both doses caused significant elevations in DNA oxidation that were maintained between 1 and 4 hours after exposure, and occurred at day 14 and day 17 of pregnancy, which they say indicates that there is a broad window period of risk.
The exposed mice also had impairments in motor coordination 6 weeks after birth that persisted up to at least 12 weeks of age.
In conclusion, the scientists say their findings raise the concern that methamphetamine use during pregnancy may result in 'long-term and possibly permanent detrimental consequences to the developing fetus'.
The paper is published in Free Radical Biology and Medicine, August 2005.