Breastfeeding and Developmental Outcomes in Infants with Prenatal Cannabis Exposure: A Retrospective Cohort Study

Abstract

Background: Human milk is critical for maternal-infant health, yet concerns about cannabis exposure through milk may discourage breastfeeding. We examined the relationship between breastfeeding and developmental outcomes among infants with prenatal cannabis exposure. Methods: We used a regional perinatal data repository from an academic hospital system with universal maternal urine drug testing. Breastfeeding status was obtained from birth certificates. Developmental delay was identified through ICD-9/10 billing codes for delayed milestones or speech disorders. Infants whose mother tested positive for cannabis at delivery were included. Descriptive statistics compared demographic characteristics by breastfeeding status, and logistic regression estimated the odds of developmental delay. Results: Among 1, 520 infants born from 2013 to 2019 with a maternal positive drug test for cannabis at delivery, 818 (54%) were not breastfed, and 702 (46%) were breastfed. In unadjusted analysis, not breastfeeding was associated with increased odds of developmental delay (OR: 1.32, 95% CI: 1.00–1.76). After adjusting for maternal tobacco use, prematurity, and birth year, this association was no longer statistically significant (OR: 1.24, 95% CI: 0.93–1.67). Conclusion: In this study, developmental outcomes did not differ by breastfeeding status among infants with prenatal cannabis exposure. These findings support current guidance from professional organizations that cannabis use is not a contradiction to breastfeeding. Further research with larger sample sizes and detailed longitudinal data is needed to better assess the potential protective role of breastfeeding against developmental delay and safety in the context of maternal cannabis use.