Smoking during pregnancy has been taboo for at least a generation or two now, but with more and more states legalizing marijuana researchers are finding it too can negatively impact a baby’s health.
Researchers from the University of Buffalo Research Institute on Addiction found that prenatal marijuana use can have consequences for a baby’s size and can influence behavior issues, especially if coupled with tobacco.
Published in the March/April issue of Child Development, the study looked at 250 infants and their mothers. In 173 of the cases the infants had been exposed to tobacco and/or marijuana during pregnancy. None were exposed to substantial amounts of alcohol.
“Nearly 30 percent of women who smoke cigarettes during pregnancy also report using marijuana,” says Rina Das Eiden, PhD, RIA senior research scientist in an interview with Science Daily. “That number is likely to increase with many states moving toward marijuana legalization, so it’s imperative we know what effects prenatal marijuana use may have on infants.”
Elden found that infants who had been exposed to both tobacco and marijuana were smaller in length, weight and head size.
In fact, babies exposed to marijuana were also more likely to be smaller when compared to babies only exposed to tobacco products. This was especially true of babies who were exposed during the third trimester and was more pronounced in boys versus girls.
Babies exposed to marijuana were also more likely to be born earlier than babies who were not exposed to anything.
“We also found that lower birth weight and size predicted a baby’s behavior in later infancy,” Eiden said in an interview with Science Daily. “Babies who were smaller were reported by their mothers to be more irritable, more easily frustrated and had greater difficulty calming themselves when frustrated. Thus, there was an indirect association between co-exposure to tobacco and marijuana and infant behavior via poor growth at delivery.”
Additionally, women who were more stressed throughout pregnancy – showing signs of anger, hostility and aggression – were more likely to continue to use marijuana and tobacco for the duration. The babies’ irritability and frustration are also linked to mother’s who reported higher levels of stress.
“Our results suggest that interventions with women who smoke cigarettes or use marijuana while pregnant should also focus on reducing stress and helping them cope with negative emotions,” Eiden said in an interview with Science Daily. “This may help reduce prenatal substance exposure and subsequent behavior problems in infants.”