Effects of prenatal and postnatal cannabis use on Lactation And Maternal Bonding (LAMB) - Cannabis use in pregnancy and the postpartum period is common. Although many current studies are focusing on the potential neurodevelopmental consequences of in-utero exposure, there is a paucity of knowledge regarding the potential effects of cannabis use in the postpartum period. Given that cannabis metabolites effect dopamine release in the brain’s reward center, it is biologically plausible that cannabis use could alter the positive reinforcement that mothers get from interaction with their infants, therefore effecting their behavior. Pre-clinical data has shown differences in maternal behavior after cannabis consumption. Studies in humans have also shown a notable difference in maternal neurotransmitter release in response to their infants when comparing mothers who use substances of abuse and those who do not. After birth, infants may also be directly exposed to cannabis metabolites through breastmilk. Studies have shown that active cannabis metabolites concentrate in the breastmilk of humans. However, the absorption and effects of these metabolites have not yet been studied. Given the known benefits of breastmilk, no recommendation currently exists to discourage the practice in lactating people who use cannabis. In this study, we intend to 1) evaluate associations between cannabis use and prenatal maternal attachment, 2) evaluate associates between cannabis use and postpartum maternal bonding and self-efficacy and 3) quantify transfer of cannabis metabolites through breastmilk consumption. Our study includes two separate but related cohorts: First, a cohort of 800 pregnant people who will be followed prospectively from the third trimester of pregnancy through 8 weeks postpartum. Of these, 600 will have used cannabis at some point in their pregnancy and 200 will not have used cannabis during pregnancy or postpartum. They will complete the Maternal Antenatal Attachment Scale in their third trimester of pregnancy and the Postnatal Bonding Questionnaire and Perceived Maternal Parenting Self-Efficacy Tool at eight weeks postpartum. Scores will be compared between four groups 1) never used cannabis 2) used cannabis during pregnancy and postpartum 3) used cannabis but quit during pregnancy, returned to use postpartum 4) used cannabis but quit during pregnancy and did not return to use postpartum. The second cohort will consist of twenty breastfeeding mothers who have made the personal decision to use cannabis during breastfeeding and ten who do not use cannabis. Maternal and infant blood samples and breastmilk samples will be collected and analyzed to evaluate the transfer of cannabis metabolites from breastmilk to the infant. The results of this study will fill a knowledge gap and inform evidence-based recommendations and counseling regarding the potential risks of cannabis consumption in the postpartum period and while lactating.
