Did we mention that we are HUGE fans of Emily Oster and her substack newsletter ParentData?!?!? She recently wrote a post about marijuana and breastfeeding, and we were inspired to write another summary. So here it goes… Again…
Emily reviews two papers detailing the effects of marijuana on nursing mothers. Both papers highlight studies in which the data showed THC levels drop quickly over time in human milk.
In the first paper, 20 nursing mothers who used cannabis regularly had their milk tested. THC levels were high in the first 5-10 hours after use and remained high for about 15 hours. When their milk was tested after the 15-hour mark, little to no THC was detected. In the second paper, the nursing mothers were administered THC rather than relying on self-report. In this second paper, it was found that THC diminished quicker and showed low amounts after about 5 hours.
Emily posits that the amount of THC that an infant would receive via milk would be high right after a dose of cannabis rather than if the nursing happened after many hours (let's say 15…). Neither paper discusses the risk of cannabis to infants which would be helpful in decision-making surrounding THC use and nursing… But Emily’s main takeaway is that if you are going to participate in marijuana use and nurse your baby, you should wait “5-10 hours after consumption…”
There are so many choices to make in feeding and caring for your baby. Hopefully, this makes one of those decisions a bit easier!