Effects of prenatal marijuana exposure on neuropsychological outcomes in children aged 1‐11 years: A systematic review

Abstract

Background. Normalization of medicinal and recreational marijuana use has increased the importance of fully understanding effects of marijuana use on individual- and population-level health, including prenatal exposure effects on child development. We undertook a systematic review of the literature to examine the long-term effects of prenatal marijuana exposure on neuropsychological function in children aged 1–11 years. Methods. Primary research publications were searched from Medline, Embase, PsychInfo, CINAHL EbscoHost, Cochrane Library, Global Health, and ERIC (1980–2018). Eligible articles documented neuropsychological outcomes in children 1–11 years who had been prenatally exposed to marijuana. Studies of exposure to multiple prenatal drugs were included if results for marijuana exposure were reported separately from other substances. Data abstraction was independently performed by two reviewers using a standardized protocol. Results. The eligible articles (n=21) on data from seven independent longitudinal studies, had high quality based on the Newcastle-Ottawa Scale. Some analyses found associations (p<0.05) between prenatal marijuana exposure and decreased performance on memory, impulse control, problem solving, quantitative reasoning, verbal development, and visual analysis tests; as well as increased performance on attention and global motion perception tests. Limitations included concurrent use of other substances among study participants, potential underreporting and publication biases, non-generalizable samples, and limited published results preventing direct comparison of analyses. Conclusions. The specific effects of prenatal marijuana exposure remain unclear and warrant further research. The larger number of neuropsychological domains that exhibit decreased versus increased psychological and behavioral functions suggest that exposure to marijuana may be harmful for brain development and function.

Sex‐specific behavioural deficits induced at early life by prenatal exposure to the cannabinoid receptor agonist WIN55, 212‐2 depend on mGlu5 receptor signalling

“…Other studies demonstrated that rats prenatally and/or postnatally exposed to cannabinoids displayed motor hyperactivity at infancy and adolescence but not at adulthood (Bara et al, ; Mereu et al, ; Navarro et al, ; Silva, Zhao, Popp, & Dow‐Edwards, ). These preclinical studies are in line with human data showing that children of both sexes prenatally exposed to cannabis are hyperactive and impulsive starting around age 6 (Fried & Smith, ; Goldschmidt, Richardson, Cornelius, & Day, ; Sharapova et al, ). Altogether, the abnormal USV profile and locomotor activity displayed by WIN‐exposed male pups indicate the presence of sex‐specific deficits in social communication and locomotion at early life stages.…”

“…showing that children of both sexes prenatally exposed to cannabis are hyperactive and impulsive starting around age 6 (Fried & Smith, 2001;Goldschmidt, Richardson, Cornelius, & Day, 2004;Sharapova et al, 2018). Altogether, the abnormal USV profile and locomotor activity displayed by WIN-exposed male pups indicate the presence of sex-specific deficits in social communication and locomotion at early life stages.…”

Marijuana and the Pediatric Population

“…34 Animal studies revealed that even low levels of exposure to marijuana have adverse neurologic effects. 37 In a recent systematic review examining 7 longitudinal studies on the effects of prenatal exposure on neuropsychological function in children, investigators found varied results between the association of prenatal exposure to marijuana and a child's neuropsychological development at ages 1 to 11 years. The majority of studies demonstrated a negative impact of marijuana during pregnancy, including deficits in neuropsychological functioning, decreased attention, memory problems, and poor impulse control.…”

Women's Questions About Perinatal Cannabis Use and Health Care Providers' Responses

“…[5][6][7][8] There is evidence that some women use cannabis to alleviate pregnancy-related symptoms (e.g., nausea and vomiting) and to self-medicate symptoms of depression, anxiety, or pain. 6,[9][10][11][12][13][14][15] However, due to concerns about health risks, including low infant birthweight and potential impacts on offspring neurodevelopment, [16][17][18][19] the American College of Obstetricians and Gynecologists currently recommends that pregnant women abstain from using cannabis during pregnancy and while breastfeeding. 20 An integrative review of women's perceptions of the health effects of prenatal cannabis use found that perceived harms of cannabis use in general are decreasing over time, 8 and some pregnant women who use cannabis perceive no health risks.…”