Cannabis use in pregnancy and maternal and infant outcomes: A Canadian cross-jurisdictional population-based cohort study

• Published in: PLOS ONE
• Main Authors: Luke, Sabrina, Hobbs, Amy J., Smith, Michaela, Riddell, Catherine, Murphy, Phil, Agborsangaya, Calypse, Cantin, Christina, Fahey, John, Der, Kenny, Pederson, Ann, Nelson, Chantal
• Format: Text
• Language: English
• Published: Public Library of Science 2022
• Subjects: Research Article; British Columbia; Canada; Newfoundland
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9683571/; https://doi.org/10.1371/journal.pone.0276824

BACKGROUND: With the recent legalization of cannabis in Canada, there is an urgent need to understand the effect of cannabis use in pregnancy. Our population-based study investigated the effects of prenatal cannabis use on maternal and newborn outcomes, and modification by infant sex. METHODS: The cohort included 1,280,447 singleton births from the British Columbia Perinatal Data Registry, the Better Outcomes Registry & Network Ontario, and the Perinatal Program Newfoundland Labrador from April 1st, 2012 to March 31st, 2019. Logistic regression determined the associations between prenatal cannabis use and low birth weight, small-for-gestational age, large-for-gestational age, spontaneous and medically indicated preterm birth, very preterm birth, stillbirth, major congenital anomalies, caesarean section, gestational diabetes and gestational hypertension. Models were adjusted for other substance use, socio-demographic and-economic characteristics, co-morbidities. Interaction terms were included to investigate modification by infant sex. RESULTS: The prevalence of cannabis use in our cohort was approximately 2%. Prenatal cannabis use is associated with increased risks of spontaneous and medically indicated preterm birth (1.80[1.68–1.93] and 1.94[1.77–2.12], respectively), very preterm birth (1.73[1.48–2.02]), low birth weight (1.90[1.79–2.03]), small-for-gestational age (1.21[1.16–1.27]) and large-for-gestational age (1.06[1.01–1.12]), any major congenital anomaly (1.71[1.49–1.97]), caesarean section (1.13[1.09–1.17]), and gestational diabetes (1.32[1.23–1.42]). No association was found for stillbirth or gestational hypertension. Only small-for-gestational age (p = 0.03) and spontaneous preterm birth (p = 0.04) showed evidence of modification by infant sex. CONCLUSIONS: Prenatal cannabis use increases the likelihood of preterm birth, low birth weight, small-for-gestational age and major congenital anomalies with prenatally exposed female infants showing evidence of increased susceptibility. Additional measures ...