Prenatal cannabis exposure increases preterm, low birth weight, NICU care risks

Key takeaways:

• Prenatal cannabis exposure increased risks for preterm birth, low birth weight and NICU care.
• Cannabis exposure may also be linked to cognition, behavioral and psychiatric outcomes in early childhood.

Infants who were exposed to cannabis in utero have increased risks for being born prematurely, having a low birth weight and requiring NICU care compared with nonexposed infants, researchers reported in Addiction.

“The global increase in cannabis use among women of reproductive age also extends to pregnant women,” Maryam Sorkhou, a PhD candidate at the Centre for Complex Interventions at the Centre for Addiction and Mental Health and the Institute of Medical Science at the University of Toronto, said in a related press release. “We know that THC, the main psychoactive constituent in cannabis, can cross the placenta from mother to fetus and bind to receptors in the fetal brain. Our study adds to that knowledge by showing that prenatal exposure to cannabis heightens the risk of several adverse birth outcomes.”

Sorkhou and colleagues conducted a meta-analysis of literature on PubMed or PsycINFO databases from inception until June 2023. Researchers identified 57 studies that investigated developmental outcomes of infants, toddlers and young children with intrauterine cannabis exposure published from 1984 to 2020. The studies involved 12,901,376 infant participants.

Overall, 102,835 infants in the studies were prenatally exposed to cannabis.

Researchers noted that 20 studies examined the associations between intrauterine cannabis exposure and preterm delivery risk, 18 evaluated the risk for low birth weight and 10 evaluated the risk for NICU care. These studies demonstrated that prenatal cannabis exposure was associated with increased risks for preterm birth (OR = 1.68; 95% CI, 1.05-2.71; P = .03), low birth weight (OR = 2.6; 95% CI, 1.71-3.94; P < .001) and NICU care (OR = 2.51; 95% CI, 1.46-4.31; P < .001) compared with no prenatal cannabis exposure.

Regarding cognition, seven studies evaluated infant and toddler cognition with prenatal cannabis exposure and demonstrated that exposure may also be associated with poorer attention. In addition, several studies evaluated behavioral and psychiatric outcomes and cognitive and neurodevelopmental outcomes in early childhood in children with intrauterine cannabis exposure. These studies demonstrated that prenatal cannabis exposure may be associated with externalizing problems during infancy and early childhood development, according to the researchers.

Researchers observed no evidence for impairments in other cognitive domains or internalizing behaviors with intrauterine cannabis exposure.

“Future research should also implement standardized measures to assess cannabis use, including frequency of use, modes of administration and cannabis composition to more clearly understand the relationship between prenatal cannabis use and developmental outcomes,” the researchers wrote.

Reference:

• Cannabis use during pregnancy is associated with adverse birth outcomes. https://www.eurekalert.org/news-releases/1007712?. Published Nov. 16, 2023. Accessed Nov. 16, 2023.