Newly published data suggests that individuals who experienced prenatal cannabis exposure may not suffer neurodevelopmental deficits later in life.
The researchers, who come from Columbia University and whose findings were published this month in Pediatric and Perinatal Epidemiology, examined a cohort of 2,868 children born between the years of 1989 and 1992.
“Children whose mothers provided information on marijuana use during pregnancy were included. The primary outcome was the Clinical Evaluation of Language Fundamentals (CELF) at age 10. Secondary outcomes included the Peabody Picture Vocabulary Test (PPVT), Child Behaviour Checklist (CBCL), McCarron Assessment of Neuromuscular Development (MAND), Coloured Progressive Matrices (CPM), Symbol Digit Modality Test (SDMT) and Autism Spectrum Quotient (AQ) scores,” the researchers wrote. “Exposed and unexposed children were matched by propensity score using optimal full matching. Missing covariate data were imputed using multiple imputation. Inverse probability of censoring weighting (IPCW) was used to adjust for missing outcome data. Linear regression within matched sets, adjusted by IPCW, evaluated score differences between exposed and unexposed children. As a secondary analysis, modified Poisson regression, adjusted by match weights and IPCW, evaluated the risk of clinical deficit in each outcome following [prenatal cannabis exposure].”
In detailing their results, the researchers said that of “the 2,804 children in this cohort, 285 (10.2%) had [prenatal cannabis exposure]. After optimal full matching and [inverse probability of censoring weighting], exposed children scored similarly on [Clinical Evaluation of Language Fundamentals],” they wrote, adding that prenatal cannabis exposure “was not associated with secondary outcomes or risks of clinical deficit in any neuropsychological assessments.”
“After adjusting for sociodemographic and clinical covariates, [prenatal cannabis exposure] was not associated with worse neuropsychological test scores at age 10 or autistic traits at 19-20,” they wrote in their conclusion.
The cannabis reform group NORML touted the results, pointing out that the “study’s findings are consistent with several prior cohort studies evaluating the long-term health outcomes associated with in utero cannabis exposure.”
According to NORML, a 2017 review of those prior studies showed that “evidence base for maternal-infant health outcomes of cannabis use in pregnancy is more robust than for many other substances. … Although there is a theoretical potential for cannabis to interfere with neurodevelopment, human data drawn from four prospective cohorts have not identified any long-term or long-lasting meaningful differences between children exposed in utero to cannabis and those not.”
With cannabis laws changing at a rapid rate in the U.S., studies like the one published this month will be crucial.
Last year, a troubling trend arose in Alabama, where pregnant women in the state had been jailed for smoking cannabis.
The outlet AL.com highlighted one such case involving a 23-year-old woman named Ashley Banks, who was arrested last spring “with a small amount of marijuana and a pistol without a permit to carry.”
“Under normal circumstances, the 23-year-old from Gadsden would have been able to post bond and leave jail until her criminal trial,” the outlet reported last year. “But Banks admitted to smoking pot on the same day she found out she was pregnant – two days before her arrest. In Etowah County, that meant she couldn’t leave jail unless she entered drug rehab, leaving her in limbo for three months.”
The Washington Post reported at the time that in Etowah County “pregnant or postpartum women who are charged with endangering their fetus via drugs have to remain in jail until they complete a drug-treatment program, without an assessment of whether that condition is appropriate for them.”