Baby’s Brain at Risk with Prenatal Meth Exposure

The problem of methamphetamine use in today’s society is an ever growing problem. Women of childbearing age are among this group, leading to an increasing number of children with prenatal methamphetamine exposure.

Christine Cloak, Ph.D., of the University of Hawaii, and colleagues findings are reported online in Neurology. The researchers did MRI scans on 29 methamphetamine-exposed children 3 to 4 years old, recruited from local hospitals, drug rehabilitation centers, and the community. Using detailed interviews of the mothers, the cumulative gestational methamphetamine exposure reported averaged 58 g over 2.5 trimesters, but varied widely.

Methamphetamine has been shown to cross the placenta and impact overall fetal growth. The drug is known to act on dopamine receptors that regulate corticogenesis and are present in the brain as early as the first trimester. It also affects other catecholamine systems involved in brain development.

Cloak and colleagues found that prenatal exposure to meth (methamphetamine) may significantly impact the development of the fetal brain, especially the white brain matter. Their research showed these children may have up to a 4% reduction in certain white matter areas of the brain.

Children exposed to meth in utero also showed asymmetries in brain lateralization with greater diffusion in dopamine-rich regions of the brain. It is thought that this may account for the slower maturation of behavioral measures observed in these children with prenatal meth exposure.

The differences in the MRI’s remained significant even after controlling for prenatal exposure to nicotine, marijuana, and alcohol.

The authors noted that the study was limited by incomplete drug histories on some patients and lack of data on genetic and environmental history.

The study was supported by the National Institute on Drug Abuse and the National Center for Research Resources, the National Institute of Neurological Disorders and Stroke, and the Office of National Drug Control Policy.

Source:
"Lower diffusion in white matter of children with prenatal methamphetamine exposure"; Neurology 2009; DOI: 10.1212/01.wnl.0000346516.49126.20; Cloak CC, et al