As the legalization of smoking marijuana in some form or another has steadily grown across the United States, pregnant women have been given the warning not to participate in the use of cannabis.  

A new study out of Erasmus University Medical Center in the Netherlands, cautions that babies born to women who used marijuana throughout their pregnancy, are more likely to have abnormal brain structure posing long-term mental health consequences.  It is estimated worldwide about 2 – 13 percent of women use cannibas during pregnancy.

The researchers analyzed data of 263 children aged 6-8 years who were part of the population-based study called Generation R Study, where the children have been followed since birth.  Out of the total number of children, 96 were born to mothers who used cannabis while pregnant of which most of the women also smoked cigarettes.

During the study the researchers used magnetic resonance imaging (MRI) scans on each child to assess their brain volume and cortical thickness.  What was found was that children exposed to both cannabis and tobacco had a thicker prefrontal cortex.  This region of the brain is involved in complex cognitive behavior, planning, decision-making, working memory, and social behavior.

This is not the first time a study has warned of the consequences of pregnant women using cannabis. 

A 2015 systemic review and meta-analysis in the British Medical Journal concluded that the effects of cannabis on maternal and fetal outcomes are generally unknown.  However results showed infants exposed to cannabis in utero had a reduced birth weight and were more likely to need placement in the NICU/ICU compared with infants whose mothers did not use cannabis while pregnant. 

Infants who are born low-birth weight (5 pounds and 8 ounces or less) have increases in morbidity and mortality. In addition low-birth weight is associated with neurosensory impairments, decrease in height, decreased IQ and education achievement and increased psychopathology.  When an infant has to be placed in the NICU after birth, this is among the highest cost involved in healthcare in and outside the United States. 

Another more recent 2016 study in the journal Toxicology, found that exposing pregnant mice to marijuana smoke daily for just five minutes resulted in reduced birthweight in the pups.

As the medical and social use of marijuana is rapidly becoming more acceptable in the United States and around the world, more babies will be negatively affected by this use and globally this will need to be addressed. 

Currently in the US, twenty-five states and the District of Columbia have laws legalizing marijuana in some form.  Four states and the District of Columbia have legalized marijuana for recreational use.  Several states have also decriminalized the possession of small amounts of marijuana while others have passed medical marijuana laws allowing for limited use of this drug. 

As the growing legalization, decriminalization and medical prescription of marijuana increases, so will the potential risk to unborn babies.  Just like alcohol use, cigarette smoking, and illegal drug use is discouraged during pregnancy, use of marijuana should be added to that list.  It is not worth taking the chance of bringing a baby into the world with lifelong significant health problems that could have been completely avoided by refraining from smoking pot.