UC San Diego

Background and aims

Cannabis use disorder (CUD) during pregnancy has increased dramatically in the United States (US). This study examined the associations between prenatal CUD and adverse neonatal outcomes and heterogeneities in the associations by mothers' tobacco use status and race/ethnicity.

Design

Population-based, retrospective cohort study.

Setting

California, USA.

Participants

A total of 4.83 million mothers who delivered a live singleton birth during 2001 to 2012 and their paired infants. Data were obtained from mother-infant linked hospital discharge records and birth and death certificates. Identified by ICD-9 codes recorded at delivery, 20 237 mothers had prenatal CUD.

Measurements

Neonatal outcomes included length of gestation, preterm birth, birth weight, admission into neonatal intensive care unit, hospitalization within 1 year of birth, and death within 1 year of birth. Propensity score matching was used to balance maternal, paternal, and infant characteristics in the comparisons between infants exposed and unexposed to prenatal CUD.

Findings

CUD increased from 2.8 to 6.9 per 1000 deliveries during 2001 to 2012. Multivariable regressions in matched samples estimated that prenatal CUD was associated with greater odds of being small for gestational age (OR = 1.13, 95% CI = 1.08, 1.18), preterm birth (OR = 1.06, 95% CI = 1.01, 1.12), low birth weight (OR = 1.13, 95% CI = 1.07, 1.20), and death within 1 year of birth (OR = 1.35, 95% CI = 1.12, 1.62). Compared with infants whose mothers were tobacco non-users, infants whose mothers were tobacco users had greater odds of preterm birth, low birth weight, hospitalization, and death in association with prenatal CUD. Compared with infants whose mothers were non-Hispanic White, infants whose mothers were Hispanic had greater odds of hospitalization and death and infants whose mothers were non-Hispanic Black had greater odds of being small for gestational age in association with prenatal CUD.

Conclusion

Prenatal cannabis use disorder appears to be associated with escalated odds of major adverse neonatal outcomes, with heterogeneities in the associations by mothers' tobacco use status and race/ethnicity.