Low levels of delta-9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis, transfers to breast milk in mothers who smoke it, a small pilot study suggests.
Although the long-term neurobehavioral effect of exposure to THC on the developing brain is unclear, mothers should be “cautious using cannabis during pregnancy and breastfeeding,” the investigators warn.
“We thought it was important to do this study, and from this study, we can tell women that it transfers in low amounts, and any amount is concerning,” Teresa Baker, MD, from Texas Tech University Health Sciences Center, in Amarillo, told Medscape Medical News.
The study was published online April 9 in Obstetrics and Gynecology.
The secretion of small to moderate amounts of THC into breast milk has been reported in some older studies. However, such studies may not adequately represent the levels of THC found in breast milk today, given the amounts of THC present in newer commercialized cannabis products.
To investigate, Baker and colleagues conducted a pilot pharmacokinetic study involving eight women who smoked cannabis and were exclusively breastfeeding their 2- to 5-month-old