Understanding the Duration of Marijuana in Breast Milk: Key Insights for Nursing Mothers

Can THC from Marijuana Remain in Breast Milk Long After Consumption?

Understanding Cannabis and Breast Milk

Research indicates that THC (tetrahydrocannabinol), the primary psychoactive component of cannabis, was detected in 63% of breast milk samples collected up to six days after mothers consumed marijuana. This suggests that marijuana may accumulate in breast milk at higher concentrations than in the bloodstream. Additionally, some studies have indicated that infants exposed to THC through breast milk may experience neurodevelopmental deficits. Consequently, health professionals commonly advise against marijuana use during pregnancy and breastfeeding.

Rising Consumption Among Women

Following the legalization of cannabis in Canada and various parts of the USA, the consumption of marijuana among women in their twenties has increased significantly. Reports indicate that up to 5% of breastfeeding mothers have used cannabis in the past year. Despite the rising use, health organizations have gathered limited data on the safety of marijuana consumption during pregnancy and lactation. Alarmingly, a survey conducted in 2015 revealed that nearly 70% of women believed cannabis was harmless during these periods.

Research Initiatives

Researchers at UCSD Medical School aimed to address the uncertainty surrounding marijuana’s effects on newborns. Their study, published in the journal *Pediatrics*, aimed to determine how long THC remains in a nursing mother’s body and the concentration levels present in breast milk. The findings confirmed that THC was present in the majority of breast milk samples six days after the mothers’ last use of marijuana.

THC Transmission in Breast Milk

Understanding the Concentration of THC

Breast milk provides numerous health benefits for infants, and it is recommended that mothers exclusively breastfeed their babies for the first six months. Therefore, nursing mothers should be aware of how their consumption choices, including cannabis, can affect their children. THC and other psychoactive compounds found in cannabis are fat-soluble, meaning they can easily accumulate in the body’s fat stores and subsequently enter breast milk.

Recent studies have shown that the concentration of THC in breast milk can be 7.5 times higher than in maternal blood. This highlights the potential risks associated with cannabis use during breastfeeding.

Study Details and Findings

In a significant study published in *Pediatrics*, researchers analyzed 54 samples from 50 breastfeeding mothers, focusing on the concentrations of THC, cannabinol, and cannabidiol. They discovered that THC was present in 63% of the samples up to six days after the last marijuana use, with cannabidiol detected in 9% of the samples. Notably, cannabinol was not detected in any of the samples.

While some samples were collected without direct observation, the researchers incorporated questionnaires and interviews to gather data on mothers’ marijuana exposure. This study’s findings align with previous research indicating high concentrations of cannabinoids in breast milk.

Previous Research Correlations

Prior studies have indicated that higher marijuana use correlates with increased concentrations of THC in breast milk. Furthermore, research has shown that infants may absorb higher levels of marijuana than what is found in their mothers’ milk. One study estimated that infants could ingest about 2.5% of the amount of THC consumed by their mothers.

Despite evidence of potential neurodevelopmental deficits in infants exposed to marijuana through breast milk, results are not consistent across all studies, necessitating further research.

Call for Further Research

Need for More Studies

Given the measurable presence of THC in breast milk and its potential effects on infant development, researchers emphasize the urgent need for more studies to explore the impact of marijuana on nursing infants. In light of the existing evidence regarding cannabinoid concentrations and their duration in breast milk, healthcare professionals strongly recommend that pregnant and breastfeeding women refrain from using marijuana.

References

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2. Ko JY, Farr SL, Tong VT, Creanga AA, Callaghan WM. Prevalence and patterns of marijuana use among pregnant and nonpregnant women of reproductive age. American Journal of Obstetrics and Gynecology. 2015;213(2):201.e1.
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4. Moss MJ, Bushlin I, Kazmierczak S, et al. Cannabis use and measurement of cannabinoids in plasma and breast milk of breastfeeding mothers. Pediatric Research. 2021;90(4):861-868.
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7. Hayer S, Mendelbaum AD, Watch L, et al. Cannabis and Pregnancy: A review. Obstetrical & Gynecological Survey. 2023;78(7):411.