Guideline No. 425b: Cannabis Use Throughout Women’s Lifespans – Part 2: Pregnancy, the Postnatal Period, and Breastfeeding

Lisa E. Graves, Magali Robert, Victoria M. Allen, Sumeet Dama, Robert L. Gabrys, Robert L. Tanguay, Suzanne D. Turner, Courtney R. Green, Jocelynn L. Cook, Guideline No. 425b: Cannabis Use Throughout Women’s Lifespans – Part 2: Pregnancy, the Postnatal Period, and Breastfeeding,
Journal of Obstetrics and Gynaecology Canada, Volume 44, Issue 4, 2022, Pages 436-444.e1,
ISSN 1701-2163,



To provide health care providers with the best evidence on cannabis use and women’s health. Areas of focus include screening, dependence, and withdrawal; communication and documentation; pregnancy (including maternal and fetal outcomes); maternal pain control; postpartum care (including second-hand smoking and parenting); and breastfeeding.

Target Population

The target population includes women who are planning a pregnancy, pregnant, or breastfeeding.

Benefits, Harms, and Costs

Discussing cannabis use with women who are planning a pregnancy, pregnant, or breastfeeding allows them to make informed choices about their cannabis use. Based on the limited evidence, cannabis use in pregnancy or while breastfeeding should be avoided, or reduced as much as possible if abstaining is not feasible, given the absence of safety and long-term follow up data on cannabis-exposed pregnancies and infants.


PubMed and Cochrane Library databases were searched for articles relevant to cannabis use during pregnancy and breastfeeding published between January 1, 2018, and February 5, 2021. The search terms were developed using the MeSH terms and keywords and their variants, including cannabis, cannabinoids, cannabidiol, CBD, THC, marijuana, edible, pregnancy, pregnant, prenatal, perinatal, postnatal, breastfeed, breastfed, lactation, nursing, fetus, fetal, neonatal, newborn, and child. In terms of publication type, all clinical trials, observational studies, reviews (including systematic reviews and meta-analyses), guidelines, and conference consensus statements were included. The main inclusion criteria were pregnant and breastfeeding women as the target population, and exposure to cannabis as the intervention of interest.

Validation Methods

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

Intended Audience

All health care providers who care for women of reproductive age.


  • 1.Screening, brief intervention, and referral for treatment can be used to identify and treat cannabis use in women during pregnancy (low).
  • 2.The effectiveness of cannabis for treatment of nausea and vomiting in pregnancy is unclear (very low).
  • 3.Prenatal cannabis exposure is associated with mild fetal growth restriction (low).
  • 4.The effects of prenatal cannabis exposure on long-term outcomes through to childhood, adolescence, and adulthood have not been conclusively defined, but recent data suggest that there are persistent neurocognitive effects into adulthood (moderate).
  • 5.Although cannabis is commonly used to treat pain, there is no evidence for its use in alleviating pain during pregnancy, intrapartum and/or postpartum periods (very low).
  • 6.There is little data available to inform decisions about cannabis use during breastfeeding (low).
  • 7.Given the evidence, the safest option is to avoid cannabis use during pregnancy and breastfeeding (moderate).
  • 8.In cases where women are unable to abstain, given the apparent dose–response relationship between prenatal cannabis exposure and persistent neurocognitive effects on the fetus and/or neonate, decreasing cannabis use during pregnancy and breastfeeding can mitigate the adverse effects (moderate).


  • 1.All women should be screened for cannabis use, including during pregnancy, using a validated screening tool (strong, low).
  • 2.Women with at-risk cannabis use or cannabis use disorder should be offered brief intervention, and, if appropriate, referral for treatment (strong, low).
  • 3.If possible, health care providers should document cannabis use in pregnancy, both in the prenatal record and in the infant’s medical record (strong, low).
  • 4.Cannabis should not be used during pregnancy because prenatal exposure can increase the risk of neurobehavioural abnormalities in the child (strong, moderate).
  • 5.Health care providers should monitor women who regularly (near daily or more than twice weekly) use cannabis during pregnancy for potential intrapartum and/or postpartum withdrawal (or cannabis withdrawal syndrome) (strong, moderate).
  • 6.Health care providers should recommend that women abstain from cannabis use during breastfeeding (strong, low).

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