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Pregnant and Breastfeeding Women and Cannabis

September-October 2018

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The increasing use of cannabis among women who are pregnant or breastfeeding is a significant public health concern. Evidence suggests that prenatal exposure to cannabis may have adverse effects on the fetus and child, including fetal growth restriction and long-term neurodevelopmental and behavioral consequences.1,2,3,4 While there is insufficient data on the safety or harms of cannabis use during lactation, Δ9-tetrahydrocannabinol (THC) does transfer into maternal breastmilk and may adversely impact brain development during early infancy.2,4,5 It is recommended that pregnant and lactating women and those contemplating pregnancy be advised to avoid cannabis use.2,3,4


Increasing Cannabis Use and Perceptions of Safety

Cannabis use is increasing among women in and around their pregnancies. Among pregnant women in the U.S., self-reported past-month use of cannabis increased 62% between 2002 and 2014.6 In its Committee Opinion on Marijuana Use During Pregnancy and Lactation, the American College of Obstetricians and Gynecologists (ACOG) reported that 34% to 60% of marijuana users continued use during pregnancy, with many women believing that it is relatively safe to use during pregnancy.2 A study from the United States National Survey on Drug Use and Health found that the percent of women who believed that regular marijuana use was of no risk during pregnancy increased from 4.6% in 2005 to 19% in 2015.7

In particular, pregnant women may be using cannabis to treat morning sickness.4,8 In a large, diverse sample of pregnant women in Northern California undergoing universal marijuana screening (urine toxicology test and self-report) in the first trimester, women with nausea and vomiting of pregnancy (NVP) were 2 to 4 times more likely to have a positive screen for cannabis than pregnant women without NVP.9 Both social media and cannabis dispensaries may be recommending cannabis as an anti-emetic in pregnancy.4,10 A recent study of licensed Colorado dispensaries found that nearly 70% recommended cannabis products to a woman reporting nausea in the first trimester.10



Both ACOG and the American Academy of Pediatrics (AAP) have published evidence-based guidelines regarding cannabis use during pregnancy and lactation. The following recommendations are adapted from the ACOG Committee Opinion and AAP Clinical Report.

  • Ask women who are pregnant, contemplating pregnancy, or breastfeeding about cannabis use (as well as their use of tobacco, alcohol, and other drugs).2 If cannabis use is causing the patient problems and she is amenable to treatment, refer her to substance use disorder treatment. (See “Screening and Referral for Cannabis Misuse and Substance Use Disorders” supplement.)
  • Women reporting cannabis use should be counseled regarding potential adverse health consequences of continued use during pregnancy and breastfeeding.2,4 (See "Counseling Patients.")
  • Women who are pregnant, contemplating pregnancy, or breastfeeding should be encouraged to discontinue cannabis use.2,4 As breastfeeding has many valuable benefits for both the mother and infant, clinicians should encourage mothers to breastfeed and should recommend that cannabis use be discontinued.4
  • Pregnant women who use cannabis for medicinal purposes should be encouraged to consider alternative therapies for which there are better pregnancy-specific safety data.2,4 In particular, as pregnant women with nausea and vomiting may be self-treating with cannabis,4 clinicians should inquire about cannabis use, counsel about lack of safety data and possible harms, and offer safer alternatives to treat NVP.8

The Mother to Baby: Medications and More During Pregnancy and Breastfeeding website provides evidence-based information for clinicians and patients on the safety of medications during pregnancy and while breastfeeding.


Counseling Patients

The following counseling points are adapted from the California Cannabis Health Information Initiative “Pregnant and Breastfeeding Women and Cannabis” fact sheet.

Cannabis Can Harm Your Baby

Consuming cannabis (marijuana, weed, pot, etc.) can affect the health of your baby and is not recommended for women who are pregnant or breastfeeding, or who plan to become pregnant soon.

Research shows that if you use cannabis while you are pregnant or breastfeeding:

  • Your baby may be born with a lower birth weight.1,11 A low birth weight baby is more likely to have health problems, especially in the first year of life.12 
  • The growth and development of your baby’s brain can be harmed.13,14

How Cannabis Affects Your Baby

No matter how you use cannabis (smoking, dabbing, vaping, eating, or drinking), one of the main active components in cannabis, THC, will reach your baby in three ways:

  • Through your bloodstream and into the placenta (the organ that feeds your baby during pregnancy).15,16
  • Through your breast milk.5,17,18 “Pumping and Dumping” doesn’t work. THC is stored in fat cells and is slowly released into your breast milk over several weeks.19
  • Through secondhand smoke that enters your baby’s lungs.20,21


Further Reading





  1. National Academies of Sciences, Engineering, and Medicine. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Washington, DC: The National Academies Press; 2017. doi:10.17226/24625
  2. Marijuana use during pregnancy and lactation. Committee Opinion No. 722. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2017;130:e205–9. doi:10.1097/01.AOG.0000467192.89321.a6
  3. Jansson LM, Jordan CJ, Velez ML. Perinatal Marijuana Use and the Developing Child. JAMA. 2018;320(6):545. doi:10.1001/jama.2018.8401
  4. Ryan SA, Ammerman SD, O’Connor ME. Marijuana Use During Pregnancy and Breastfeeding: Implications for Neonatal and Childhood Outcomes. Pediatrics. 2018;142(3):e20181889. doi:10.1542/peds.2018-1889a
  5. Bertrand KA, Hanan NJ, Honerkamp-Smith G, Best BM, Chambers CD. Marijuana Use by Breastfeeding Mothers and Cannabinoid Concentrations in Breast Milk. Pediatrics. 2018;142(3):e20181076. doi:10.1542/peds.2018-1076
  6. Brown QL, Sarvet AL, Shmulewitz D, Martins SS, Wall MM, Hasin DS. Trends in Marijuana Use Among Pregnant and Nonpregnant Reproductive-Aged Women, 2002-2014. JAMA. 2017;317(2):207. doi:10.1001/jama.2016.17383
  7. Jarlenski M, Koma JW, Zank J, Bodnar LM, Bogen DL, Chang JC. Trends in perception of risk of regular marijuana use among U.S. pregnant and non-pregnant reproductive-aged women. Am J Obstet Gynecol. 2017;217(6):705-707. doi:10.1016/j.ajog.2017.08.015
  8. Westfall R, Janssen P, Lucas P, Capler Rl. Survey of medicinal cannabis use among childbearing women: Patterns of its use in pregnancy and retroactive self-assessment of its efficacy against ‘morning sickness'. Complement Ther Clin Pract. 2009;15(4):242-246. doi: 10.1016/j.ctcp.2009.07.001
  9. Young-Wolff KC, Sarovar V, Tucker LY, et al. Association of Nausea and Vomiting in Pregnancy with Prenatal Marijuana Use. JAMA Intern Med. Published online August 20, 2018. doi:10.1001/jamainternmed.2018.3581
  10. Dickson B, Mansfield C, Guiahi M, et al. Recommendations From Cannabis Dispensaries About First- Trimester Cannabis Use. Obstet Gynecol. 2018;131(6):1031-1038.doi:10.1097/AOG.0000000000002619
  11. Gunn JK, Rosales CB, Center KE, et al. Prenatal exposure to cannabis and maternal and child health outcomes: a systematic review and meta-analysis. BMJ Open. 2016;6(4):e009986. doi:10.1136/bmjopen-2015-009986
  12. U.S. Department of Health and Human Services, Health Resources and Services Administration, Maternal and Child Health Bureau. Child Health USA 2014. Rockville, Maryland: U.S. Department of Health and Human Services; 2014.
  13. Wu CS, Jew CP, Lu HC. Lasting impacts of prenatal cannabis exposure and the role of endogenous cannabinoids in the developing brain. Future Neurol. 2011;6(4):459-480.
  14. Leech SL, Richardson GA, Goldschmidt L, Day NL. Prenatal substance exposure: effects on attention and impulsivity of 6-year-olds. Neurotoxicol Teratol. 1999;21(2):109-118.
  15. Bailey JR, Cunny HR, Paule MG, and Slikker W. Fetal disposition of delta 9-tetrahydrocannabinol (THC) during late pregnancy in the rhesus monkey. Toxicol Appl Pharmaco. 1987;90(2):315-321. doi:10.1016/0041-008x(87)90338-3
  16. Hutchings DE, Martin BR, Gamagaris Z, Miller N, Fico F. Plasma concentrations of delta-9-tetrahydrocannabinol in dams and fetuses following acute or multiple prenatal dosing in rats. Life Sci. 1989;44(11):697-701.
  17. Garry A, Rigourd V, Amirouch A, Fauroux A, Aubry S, Serreau R. Cannabis and breastfeeding. J Toxicol 2009:596149. doi:10.1155/2009/596149
  18. Perez-Reyes M, Wall ME. Presence of delta9-tetrahydrocannabinol in human milk. N Engl J Med. 1992; 307(13):819-20. doi: 10.1056/nejm198209233071311
  19. Reece-Stremtan S, Marinelli KA. ABM clinical protocol #21: guidelines for breastfeeding and substance use or substance use disorder, revised 2015. Breastfeed Med. 1995;10(3):135-41. doi:10.1089/bfm.2015.9992
  20. Herrmann ES, Cone, EJ, Mitchell JM, et al. Non-smoker exposure to secondhand cannabis smoke II: Effect of room ventilation on the physiological, subjective, and behavioral/cognitive effects. Drug Alcohol Depend. 2015;151(1):194-202. doi:10.1016/j.drugalcdep.2015.03.019
  21. Moore C, Coulter C, Uges D, et al. Cannabinoids in oral fluid following passive exposure to marijuana smoke. Forensic Sci Int. 2010;212(1):227-230. doi:10.1016/j.forsciint.2011.06.019

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Author Information:

Eloisa Gonzalez MD, MPH
Director, Cardiovascular and School Health*
Director, Integrative Medicine, The Wellness Center at LA County Historic General Hospital**

Gary Tsai, MD, FAPA, FASAM
Medical Director and Science Officer, Substance Abuse Prevention and Control*

Jeff Chen MD, MBA
Director, Cannabis Research Initiative***

Sarah Guerry, MD
Chief, Medical Education and Communication*

*County of Los Angeles
Department of Public Health

**County of Los Angeles
Department of Health Services

***University of California,
Los Angeles

Rx for Prevention, 2018

Published: September 13, 2018