2018 | United States | Observational laboratory analysis
Bertrand KA et al. Pediatrics. 2018;142:e20181076.
Methods: Fifty breastfeeding women reporting cannabis use provided 54 milk samples to a research repository. Investigators measured cannabinoid concentrations using mass spectrometry and examined reported timing and frequency of use.
Findings: THC was measurable in 34 of 54 samples, or 63%, including samples collected up to approximately six days after last reported use. Concentrations varied substantially.
Limitations: Use and timing were self-reported, and sampling was not a controlled dosing experiment. The study measured exposure rather than infant health outcomes. Its longest detection interval does not establish a universal clearance time.