The increasing prevalence of cannabis use has led to questions among breastfeeding parents about its safety for their infants. Parents are concerned about how substances they consume might affect their child’s health. This article aims to provide current knowledge regarding cannabis use while breastfeeding, focusing on how compounds transfer, their documented effects on infants, and the guidance offered by health authorities.
Transfer of Compounds into Breastmilk
Cannabis contains various compounds, with delta-9-tetrahydrocannabinol (THC) being the primary psychoactive component. THC readily transfers from the mother’s bloodstream into breastmilk because it is highly fat-soluble. This fat-soluble nature allows THC to accumulate in the body’s fat stores, including the high fat content of breastmilk itself, which can act as a reservoir for the compound. The concentration of THC in breastmilk can be higher than in the mother’s bloodstream, with some studies reporting milk-to-plasma ratios as high as 6:1 or 8:1.
Once transferred, THC can persist in breastmilk for an extended duration. Studies have detected THC in breastmilk for varying periods, ranging from 6 days to more than 6 weeks after maternal use. The half-life of THC in breastmilk has been estimated to average around 27 hours in some studies, but can extend to about 17 days in others, depending on factors like frequency of use and individual metabolism. This prolonged presence means that even occasional use may result in continued infant exposure. Other cannabinoids, such as cannabidiol (CBD), and their metabolites may also transfer into breastmilk.
Documented Effects on Infants
Exposure to cannabis compounds through breastmilk raises concerns about potential effects on infants, particularly regarding their developing brains. Tetrahydrocannabinol (THC) can affect a newborn’s brain development and may contribute to hyperactivity and poor cognitive function. Research suggests that early exposure to cannabis could lead to subtle yet lasting neurofunctional changes.
Some studies have explored specific developmental outcomes in infants exposed to cannabis via breastmilk. One study found a decrease in infant motor development at one year of age among those whose mothers used cannabis daily or nearly daily during the first month postpartum. However, this effect was not observed with occasional maternal cannabis use. Other research has indicated potential impacts on sleep patterns, with some exposed infants showing abnormal sleep patterns, including decreased quiet sleep and increased sleep motility.
While some studies have not found significant differences in growth or mental and motor development in infants exposed to cannabis through breastmilk, the overall body of research is limited and sometimes conflicting. It is often difficult to isolate the precise effects of cannabis delivered through breastmilk from other potential influences, such as prenatal exposure or secondhand smoke. The potency of cannabis products has also increased significantly over recent decades, meaning older studies might not fully reflect current risks.
Guidance from Health Authorities
Major health organizations consistently advise against cannabis use during breastfeeding due to potential risks to the infant and the current lack of comprehensive safety data. The American Academy of Pediatrics (AAP) recommends that women who are breastfeeding avoid cannabis use. This recommendation is based on concerns that the long-term effects of exposure are not fully known but could be harmful to the child.
Similarly, the Centers for Disease Control and Prevention (CDC) advises breastfeeding mothers not to use marijuana or products containing cannabinoids like THC and CBD. They emphasize that chemicals from cannabis can pass into breastmilk and potentially affect brain development. The American College of Obstetricians and Gynecologists (ACOG) also discourages cannabis use during breastfeeding, stating that data are insufficient to evaluate its effects on infants and that potential risks are unknown. Parents should discuss any cannabis use with a healthcare provider to ensure the safest choices for their child’s health.