Abstract
Background
Information on cannabinoids in breast milk and maternal cannabis use is limited. We quantified cannabinoids in plasma and breast milk of breastfeeding mothers and assessed cannabis use patterns.
Methods
This is a prospective study at a university hospital in a state with legal medical and recreational cannabis. Breast milk and plasma samples along with survey data were collected from volunteers using cannabis in the last 48 h at 2 weeks and 2 months postpartum.
Results
Twenty subjects were enrolled. Median age (IQR) was 27 (24–34) years. Median (IQR) instances of cannabis use in the last 7 days were visit 1: 17 (6–29) and visit 2: 23 (15–45). Median (IQR) tetrahydrocannabinol (THC) concentrations were: plasma 3.7 ng/ml (0.8–56.8) and breast milk 27.5 ng/ml (0.8–190.5). Median (IQR) cannabidiol (CBD) concentrations were: plasma 0.6 ng/ml (0.5–6.4) and breast milk 1.2 ng/ml (0.5–17.0). Median (IQR) THC M/P: 7.0 (1.8–34.6) and CBD M/P: 2.6. Median breast milk THC concentration increased from visit 1 to visit 2 by 30.2 ng/ml (95% CI 3.05–69.3 ng/ml).
Conclusions
THC and CBD accumulate in breast milk. Breastfeeding mothers used cannabis frequently and increased use in the early postpartum period. Research on the effects of infant exposure to cannabinoids in breast milk is urgently needed.
