With marijuana legal in 29 states and the District of Columbia (D.C.) for medical use, eight states and D.C. for recreational use, and soon to be legal in all of Canada for medical and recreational use, researchers are becoming increasingly interested in learning about the birth outcomes of children of pregnant and postpartum women who use marijuana, as well as the effects on the mother herself.
According to the Canadian Centre on Substance Abuse, prenatal exposure to cannabis has been found to adversely affect children’s cognitive development, academic achievement, as well as increase the likelihood of behaviors such as attention deficits, hyperactivity and impulsivity.
Although there have been earlier studies done on the use of marijuana, authors of a current study on marijuana use during and after pregnancy, soon to be published in the Journal of Drug and Alcohol Dependence write that the older studies are limited when it comes to examining associations between marijuana use during pregnancy.
A 2009 study found a link between learning and development impairments in adolescents who were exposed to marijuana in utero. As a result, in 2015, the American College of Obstetricians and Gynecologists (ACOG) recommended discontinuing marijuana use during pregnancy. OB/GYNs are also discouraged from prescribing marijuana to pregnant women for medicinal purposes and since cannabis can be detected in breast milk, women are also encouraged to stop using marijuana if they are breastfeeding.
The current soon-to-be-published study had three main objectives: 1) to examine the socio-demographics of women who use marijuana; 2) to examine the relationship between marijuana use and low birth weight; and 3) to examine any link between marijuana use and postpartum depression and breastfeeding.
“As more states legalize medical or recreational marijuana and access to marijuana increases,” note the study authors, “there is a need to understand the extent that women use marijuana during and after pregnancy and correlates of use.”
Researchers used state-specific data from the Pregnancy Risk Assessment Monitoring System conducted by health departments in New York along with the Centers for Disease Control and Prevention. Information was obtained from three states over a time period of three years – Alaska, Hawaii, and Vermont. Over nine thousand women participated in the study by filling out a questionnaire two to nine months after giving birth.
The data showed that on average, 4.2 per cent of pregnant women used marijuana and were more likely to be under 24 year of age, cigarette smokers and alcohol drinkers. Alaska, which legalized marijuana for recreational use in 2014, reported a slightly higher average with 6.6 per cent of pregnant women reporting marijuana use. Hawaii showed the least percentage of marijuana use by pregnant women at 2.8 per cent.
Data also revealed that pregnant women using marijuana were more likely to have experienced a higher number of stressors in the year before birth than non-users as well as binge drinking during the last three months of pregnancy.
In the postpartum period, researchers found that on average, 6.8 per cent of women who participated in the study were marijuana users. As well as lower infant birthweight and shortened breastfeeding (less than eight weeks), researchers found that postpartum marijuana use was also linked to postpartum depressive symptoms (14 per cent versus 9 per cent).
“As ACOG recommends, clinicians should screen for marijuana use as part of a comprehensive substance use screening,” recommends the authors of the study. “Surveillance of marijuana use among pregnant and postpartum women is critical to better understanding the relationship of marijuana use with birth outcomes, postpartum depression and breastfeeding, as well as infant neurodevelopment outcomes.”
Ko, Jean Y., Tong, Van T., Bombard, Jennifer M., Hayes, Donald K., Davy, John, Perham-Hester, Katherine A., (May 2018), Drug and Alcohol Dependence, Marijuana use during and after pregnancy and association of prenatal use on birth outcomes: A population-based study, https: //doi.org/10.1016/j.drugalcdep.2018.02.107
Amy J. Porath-Waller, Ph.D. Director, Research and Policy, CCSA, 2015, Clearing the Smoke on Cannabis Maternal Cannabis Use during Pregnancy – An Update, http://www.ccsa.ca/Resource%20Library/CCSA-Cannabis-Maternal-Use-Pregnancy-Report-2015-en.pdf
Patricia Tomasi is a mom, maternal mental health advocate, journalist, and speaker. She writes regularly for the Huffington Post Canada, focusing primarily on maternal mental health after suffering from severe postpartum anxiety twice. You can find her Huffington Post biography here. Patricia is also a Patient Expert Advisor for the North American-based, Maternal Mental Health Research Collective and is the founder of the online peer support group - Facebook Postpartum Depression & Anxiety Support Group - with over 1500 members worldwide. Blog: www.patriciatomasiblog.wordpress.com