Cannabis Use During Lactation – A Scoping Review

Context: Cannabis of any form can be passed from a mother to her infant through breast milk, potentially affecting their neurodevelopment. Females self-report multiple reasons for the use during lactation. Cannabis is the most commonly used illicit drug during pregnancy while the prevalence of cannabis use during lactation is unknown.

Objective: To evaluate the relationship between cannabis use by lactating females and the impact on the health and development of breastmilk-fed children.

Study Design and Analyses: Scoping Review.

Setting or Dataset: PubMed, Embase, Science Direct, Scopus, and PsychInfo.

Population Studied: Breastfeeding females cannabis – users and their infants.

Intervention/Instrument: We searched for published articles in PubMed, Embase, Science Direct, Scopus, and PsychInfo databases from inception through February 2023. Eligible publications involved human subjects, were published in English, and described cannabis use during lactation and potential fetal implications. Systematic data extraction was completed for each eligible study.

Outcome Measures: Prevalence of breastfeeding females, Prevalence of infants with neurodevelopmental concerns, Dose of cannabis found in females’ breastmilk, dose of cannabis in breastfed infants.

Results: These studies were methodologically heterogeneous, including 3 prospective studies, 1 pharmacokinetic study, 1 cross-sectional study, and 1 retrospective medical record review, with sample sizes that varied from 8-3285 female patients. Results suggested that cannabis can pass through breastmilk from mother to child and there is a strong correlation between prenatal and postnatal cannabis use. Results indicate conflicting outcomes regarding the risk of exposure to cannabis in lactation.

Conclusions: Research on the impact of cannabis use by lactating females on their breastmilk-fed children is limited yet suggests that cannabis is present in breastmilk and absorbed by breastfed children. Given the widespread cannabis use, including by lactating females, more research is urgently needed to elucidate the character of breastmilk-related transmission of cannabis and its impact on developing children and to tailor interventions for reducing potential cannabis-related harm.