Montreal, Canada: Prenatal cannabis use does not impede infants’ cognitive development, according to longitudinal data published in Maternal and Child Health Journal.
Canadian investigators assessed the prevalence of prenatal cannabis use and its impact on early childhood development in a cohort of 1,489 mothers and infants.
They reported that instances of prenatal cannabis use were low (below three percent) and that most mothers who acknowledged using it ceased doing so after their first trimester. Prenatal cannabis use was associated with lower socioeconomic status, prenatal use of alcohol and tobacco, and more distress symptoms during the first trimester of pregnancy.
Investigators reported no association between prenatal cannabis use and developmental indicators at age two, including fine motor skills and language development. However, researchers did not rule out the possibility of such changes developing later in life.
“We found that cannabis use during pregnancy was not significantly associated with cognitive, fine motor, gross motor and language development of 2-year-old children,” the study’s authors concluded. “This [null finding] might suggest that associations of low magnitudes are more likely to appear at developmental stages when higher developmental functions emerge.”
Prior studies assessing the potential impacts of in-utero cannabis exposure on early childhood health have yielded inconsistent results. While some observational studies have identified a link between exposure and low birth weight or an increased risk of preterm birth, other studies have not. A literature review published in the journal Preventive Medicine concluded, “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.”
Full text of the study, “Longitudinal associations between cannabis use during pregnancy and child cognitive, motor, and language development at 2 years old,” appears inMaternal and Child Health Journal.