Scale to assess newborns exposed to methamphetamine may predict later problems

A scale used to assess the behaviour of newborns exposed to methamphetamine before birth might be able to identify those children who will develop problems later on.

A large body of research shows that prenatal exposure to cocaine can lead to cognitive and behavioural problems in children.

According to study co-author Barry M. Lester, PhD., recently, methamphetamine has become the drug of choice for many pregnant drug users.

Despite its widespread use, little is known about the potential consequences of prenatal meth exposure on the development of children.

Lester and his colleagues undertook the Infant Development, Environment, and Lifestyle (IDEAL) Study to look at the neurobehavioral effects of prenatal meth exposure in 185 newborns at four clinical centres.

A comparison group included 195 newborns who were not exposed to methamphetamine but were exposed prenatally to alcohol, tobacco or marijuana.

This allowed researchers to tease out any effects due to methamphetamine exposure rather than effects that may have been due to other substances commonly used in conjunction with meth.

Researchers used the NICU Network Neurobehavioral Scale (NNNS) to evaluate the newborns during the first four days of life and again at 1 month of age.

The NNNS assesses muscle tone, reflexes, behavioural state, motor development and stress.

“There are certain characteristics that are real clues to whether or not the baby does well later on. Stress is one of them, arousal is another,” Lester, who has studied babies exposed to cocaine in utero, said.

Results showed that newborns whose mothers used methamphetamine while pregnant were hard to arouse, but once awakened, they could not be calmed easily.

At 1 month, improvements were seen in arousal and total stress among the methamphetamine-exposed group. In addition, both groups showed higher quality of movement, less lethargy and fewer asymmetric reflexes.

“The beauty of these data is showing that we can identify the kids who are doing well, those that improved,” Lester said.

“We can also pull out the ones who are not doing as well and arrange intervention and prevention services for them before some abnormality shows itself,” he stated.

Lester noted that many babies are labelled “high-risk”, but there aren”t enough resources to provide treatment services to all of them.

If those likely to develop problems later on can be identified based on neurobehaviour shortly after birth, then intervention services can be targeted to that group.