The prevalence and significance of gestational cannabis use at an Australian tertiary hospital

Abstract

BackgroundCannabis is one of the most common non‐prescribed psychoactive substances used in pregnancy. The prevalence of gestational cannabis use is increasing.AimThe aim was to examine the prevalence of gestational cannabis use and associated pregnancy and neonate outcomes.Materials and MethodsA retrospective observational study involving pregnant women delivering in 2019 was conducted at a tertiary hospital in Perth, Western Australia. Gestational cannabis and other substance use records were based on maternal self‐report. Pregnancy outcomes included neonatal gestational age, birthweight, birth length, head circumference, resuscitation measures, special care nursery admission, 5‐min Apgar score and initial neonatal feeding method.ResultsAmong 3104 pregnant women (mean age: 31 years), gestational cannabis use was reported by 1.6% (n = 50). Cannabis users were younger, more likely to use other substances and experience mental illness or domestic violence compared with non‐users. Neonates born to cannabis users had a lower mean gestational age, birthweight and birth length compared to those born to non‐cannabis users. Gestational cannabis use (odds ratio (OR) 3.3, 95% confidence interval (CI) 1.6–6.7) and tobacco smoking (OR 2.2, 95% CI 1.5–3.6) were associated with increased odds of a low‐birthweight neonate. Combined cannabis and tobacco use during pregnancy further increased the likelihood of low birthweight (LBW, adjusted OR 3.9, 95% CI 1.6–9.3). Multivariate logistic regression analysis adjusted for maternal sociodemographical characteristics, mental illness, alcohol, tobacco and other substance use demonstrated gestational cannabis use to be independently associated with LBW (OR 2.3, 95% CI 1.1–5.2).ConclusionGestational cannabis use was independently associated with low birthweight, synergistically affected by tobacco smoking.

Maintaining the momentum of curiosity over cannabis use in pregnancy

“…We read with great interest your well-planned and executed article on cannabis use within the pregnant population attending your institution in Western Australia. 1 As you infer in your surmise, cannabis use in pregnancy as a causality of fetal growth restriction is not proven, but an association is certainly apparent. Perhaps studies like your large audit may be able to influence maternity data collection sets to explore the causality question in greater detail.…”

Cannabinoid hyperemesis syndrome in pregnancy: Challenges and opportunities

“…[6][7][8][9] Women in the 20 to 29-year-old age group, experiencing mental ill health, domestic violence or those from lower socio-economic backgrounds are predisposed to higher antenatal cannabis uptake and/or continuation. 1,7,9…”

“…2 Combined cigarette smoking and cannabis use significantly increased the risk of fetal growth restriction (OR 4.7, 95% CI 1.2-18.7), pre-term birth (OR 2.8, 95% CI 1.2-6.9) and LBW (OR 3.9, 95% CI 1.6-9.3). 1 Longitudinal cohort studies suggest long-term neurodevelopmental impacts, such as childhood attention deficits and learning delays. 3 However, findings are inconclusive and require further elucidation.…”

“…Antenatal cannabis consumption is associated with adverse perinatal outcomes. [1][2][3] Cannabinoid hyperemesis syndrome (CHS), a debilitating constellation of abdominal pain, cyclical vomiting and intractable nausea, occurs with heavy cannabis use and may lead to serious maternal-fetal morbidity. 4 In addition to the diagnostic difficulty CHS poses for obstetricians, little evidence exists for safe therapeutic agents during pregnancy.…”

“…Cannabis remains the most widely consumed illicit substance internationally with increasing rates of cannabis consumption. Antenatal cannabis consumption is associated with adverse perinatal outcomes 1–3 . Cannabinoid hyperemesis syndrome (CHS), a debilitating constellation of abdominal pain, cyclical vomiting and intractable nausea, occurs with heavy cannabis use and may lead to serious maternal‐fetal morbidity 4 .…”