Prenatal cannabis exposure and childhood outcomes: Results from the ABCD study

In light of increasing cannabis use among pregnant women, the Surgeon General of the United States issued an advisory against the use of marijuana during pregnancy on August 29th, 2019.To determine whether cannabis use during pregnancy is associated with adverse outcomes among offspring.Cross-sectional analysis of the baseline session of the ongoing longitudinal Adolescent Brain and Cognitive Development (ABCD) study.Data were collected from 22 sites across the United States between 2016 and 2018.Children ages 9-11 (n=11,489) and their parent or caregiver.Prenatal marijuana exposure prior to and following maternal knowledge of pregnancy.Child psychopathology symptomatology (i.e., psychotic-like experiences and internalizing, externalizing, attention, thought, and social problems), cognition, sleep, birth weight, gestational age at birth, body mass index (BMI), and brain structure (i.e., total intracranial volume, white matter volume, gray matter volume). Covariates included familial (e.g., income, familial psychopathology), pregnancy (e.g., prenatal vitamin use, whether the pregnancy was planned), and child (e.g., birth weight, substance use) variables.Among 11,489 children (age 9.9±0.6 years; 47.78% female), 655 (5.70%) were prenatally exposed to cannabis in total. Marijuana use prior to (n=648; 5.64%) and following (n=242; 2.11%) maternal knowledge of pregnancy were associated with increased offspring psychopathology characteristics (i.e., psychotic-like experiences and internalizing, externalizing, attention, thought, social, and sleep problems) and BMI as well as reduced cognition, birth weight, and brain structure (i.e., total white and gray mater volumes; all psfdr<.007), but not gestational age at birth. Exposure following maternal knowledge of pregnancy remained significantly associated with psychopathology, cognition, and birth weight outcomes when including potentially confounding variables (all ps<0.046). All associations with exposure prior to maternal knowledge of pregnancy were nonsignificant when considering potentially confounding variables (all ps>0.06).Prenatal cannabis exposure, and its correlated factors, may increase risk for psychopathology and reduced cognition during middle childhood as well as reduced birthweight. Consistent with recent recommendations by the Surgeon General, marijuana use during pregnancy should be discouraged.