Study shows smoking cannabis during pregnancy 'impairs memory, decision-making and personality' of the baby

Pregnant women who smoke cannabis risk causing damage to their unborn baby's brain, experts have warned. The drug is linked to abnormal brain structure in children, a new study has revealed. Those children exposed to marijuana in the womb were found to have a thicker prefrontal cortex region of the brain, when compared to children not exposed to the drug. The prefrontal cortex is a region of the brain that is linked to decision-making, memory and personality.
The study's author, Dr Hanan El Marroun, of the Erasmus University Medical Center in The Netherlands, said: 'This study is important because cannabis use during pregnancy is relatively common and we know very little about the potential consequences of cannabis exposure during pregnancy and brain development later in life.'
The field of research is an emerging one, as the legalization of cannabis becomes more widespread. An estimated two to 13 per cent of women across the world use the drug while they are pregnant. And, previous research has identified short and long-term behavioral consequences of prenatal cannabis exposure. But, the effect the drug has on brain morphology in offspring, were unknown.
Dr El Marroun said: 'Understanding what happens in the brain may give us insights in how children develop after being exposed to cannabis.'

The drug was found to cause a child's prefrontal cortex (highlighted in green at the front of the brain) to be thicker

She and her team of researchers used structural magnetic resource imaging (MRI) scans to examine the brains of 54 children, all aged between six and eight years old. All of the 54 children had been exposed to cannabis while they were in the womb. Meanwhile, the researchers discovered most of those children exposed to marijuana had also been exposed to tobacco. As a result, they also examined brain scans of 96 children, exposed to just tobacco in the womb, as well as a group of 113 control children with no exposure to either drug. Researchers compared the brain scans of all three groups. They noted differences in the thickness of the prefrontal cortex, it being thicker in children exposed to cannabis. The researchers say their findings suggest cannabis exposure has different effects than tobacco. No differences were found in overall brain volume in those children exposed to cannabis.
'This important study suggests that prenatal exposure to cannabis could have important effects on brain development.'
Dr El Marroun added: 'We have to be careful interpreting the results of the current study.'
He said further research  is needed to explore the causal nature of the relationship between prenatal cannabis exposure and structural brain abnormalities.
She said: 'Nevertheless, the current study combined with existing literature does support the importance of preventing smoking cannabis and cigarettes during pregnancy.'