Duration of Marijuana Concentration in Breast Milk- A Pilot Study

Legalization of marijuana in Colorado for both medicinal and recreational purposes has led to a perception of its safety, which has not been well studied in pregnant or lactating women. The psychoactive component of marijuana, delta-9-tetrahydrocannabinol (THC) is lipophilic and therefore presumed to be secreted into breast milk. Additionally, the difference between modes of consumption (ie. smoked vs. edible) has not been well described in regards to THC concentration in breast milk. The purpose of this small pilot study is to describe the presence and duration of THC expression in breast milk among women who have evidence of THC exposure at the time of labor and delivery or within 72 hours of delivery. The researchers hypothesize that women with positive urine drug screen for THC within 72 hours of delivery may excrete THC in breast milk for a predicted period of time, and therefore the aim of this project is to determine timing to safely return to breastfeeding to decrease infant exposure to THC. The specific aims are to determine in women who test positive for THC at delivery: 1. Determine length of time THC and metabolites are detected in breast milk of mothers who have a positive urine drug screen at the time of presentation for labor and delivery or within 72 hours of delivery. 2. Determine length of time THC and metabolites are detected in breast milk of mothers with postnatal exposure of either ingested or inhaled marijuana, to inform recommendations on when to safely return to breastfeeding. 3. Describe modes of marijuana consumption in women presenting for delivery and correlate with THC concentrations and persistence in breast milk.