Pregnant Canadians’ Perceptions About the Transmission of Cannabis in Pregnancy and While Breastfeeding and the Impact of Information From Health Care Providers on Discontinuation of Use

OBJECTIVE: Rates of cannabis use during pregnancy and while breastfeeding are increasing in Canada. Some observational studies have found associations between cannabis use in pregnancy and low birthweight, preterm labour, and admission to the intensive care unit. This study aimed to evaluate women's perceptions about transmission of cannabis to the fetus, and whether receiving information from a health care provider influenced their decision to stop using cannabis during pregnancy. METHODS: Pregnant women presenting to obstetrical, midwifery, and family practice clinics in the greater Hamilton, Ontario area were asked to complete an anonymous survey. Chi-square tests were used to investigate whether patient knowledge was influenced by health care providers or by self-directed learning and if this information influenced their decision to discontinue cannabis use. RESULTS: Of the 478 women surveyed, the vast majority perceived that cannabis is transmitted to the fetus during pregnancy and to the infant while breastfeeding (94.3% and 91.2%, respectively). The majority of women (99%) indicated that the advent of cannabis legalization did not influence their choice to use cannabis in pregnancy. Women who continued to use cannabis during pregnancy were more likely to report receiving information on cannabis from a health care provider (52%) than those who chose to discontinue use in pregnancy (35%) (P = 0.035). CONCLUSIONS: In our study, the proportion of pregnant women who understood that cannabis could be transmitted to the fetus in utero and to the infant via breastmilk was high. Despite this, 4.2% of women reported that they continued to use cannabis in pregnancy. More work is needed to understand why some women continue to use cannabis in pregnancy despite being informed of its risks.