Pregnant cannabis smokers have children with better global motion perception

Is it better for women to smoke marijuana when they're pregnant? Probably not, but a study conducted in New Zealand shows that children who were born from mothers who imbibed in cannabis when carrying scored better in an area of brain development, as opposed to those who didn't smoke weed.

The test from Auckland University took 165 children aged four and younger and asked them to watch multiple moving dots on a screen. They were then asked to identify the main direction that the dots moved in to help the researchers assess the youngsters' global motion perception.

The children had been exposed to difference combinations of methamphetamine, alcohol, nicotine and marijuana before birth, along with 25 unexposed children.They found that the mums who smoked marijuana during pregnancy produced offspring that scored better than those that didn't. Furthermore, the more they smoked, the better their children performed.

Arijit Chakraborty, author of the study, said: "Children who were exposed to marijuana were almost 50% better at the global motion task than those who were not."

Unsurprisingly, those whose mothers drank alcohol performed worse, according to the study published in Scientific Reports, and the more the mothers drank the worse the children's scores were. When marijuana and alcohol were used by a mother, the effects cancelled each other out.

"Unexpectedly, children exposed to marijuana had significantly better global motion perception than those of children not exposed to marijuana and there was a significant interaction between the effects of alcohol exposure and marijuana exposure," Chakraborty said. "Exposure to marijuana in the absence of alcohol was associated with improved global motion perception which was significantly better than that of children who had not experienced prenatal drug exposure."

"Global motion perception for children exposed to both marijuana and alcohol was no different from that of children who had no drug exposure. This perhaps has implications for preventing some of the effects of Foetal Alcohol Syndrome."

However, Chakraborty said that this shouldn't be basis for mothers-to-be to start smoking marijuana. "We are not recommending on the basis of our findings to start smoking marijuana. Previous studies suggest marijuana had some ill effects on other neurodevelopmental domains. One improvement in one particular neurodevelopmental domain does not suggest holistically the brain is performing better," he is quoted by the New Zealand Herald as saying.

"We would recommend the mothers to stop drinking in the first place instead of trying marijuana unless subsequent research specifically answers this question."

Additionally, the effects of cannabis before birth have not been studied broadly enough but that "detrimental effects have been reported for motor and cognitive development. Therefore our results cannot be extrapolated beyond global motion perception or interpreted as marijuana having beneficial effects on foetal development.

"Previous studies have reported that prenatal exposure to heavy marijuana use impairs performance on a range of standardised neuropsychological tests of attention, memory, and executive function that involve a visual component."