Abstract
BACKGROUND: Human milk purchased via the Internet poses a potential risk of recipient infant exposure to drugs, but this risk has not been quantitated by research. Our objective was to test milk we purchased via the Internet for 13 common classes of drugs of abuse to explore the extent of possible exposure to recipient infants. MATERIALS AND METHODS: Samples (n = 102) of milk purchased via the Internet were tested for 13 groups of drugs that are commonly abused using immunoassay screening to identify suspected positives, followed by liquid chromatography/tandem mass spectrometry or gas chromatography/mass spectrometry for confirmation. Sellers' advertisements were abstracted for statements about drug use or abstinence. RESULTS: Most (71%) sellers stated in their advertisement that they abstained from some type(s) of drugs (prescription or illicit), but 29% indicated nothing about drug use or abstinence. No sellers admitted to illicit drug use in their advertisement. No samples tested positive for the selected drugs of interest (prevalence = 0%; 95% confidence interval, 0.0, 2.9). CONCLUSIONS: We did not detect any of the selected drugs in 102 milk samples. Our sample was too small to detect less commonly used drugs and to provide a narrow confidence interval around the prevalence estimate and did not include milk shared at no cost. Thus, these findings are exploratory and cannot rule out the possibility of drugs being present in other milk available via the Internet.