Babies born to mothers who used cannabis during pregnancy are at a higher risk of low birthweight, preterm birth, and admission to intensive care than those not exposed to cannabis in the womb. The corresponding study was published in the American Journal of Obstetrics and Gynecology.
“This is a large, well-designed study that adds important evidence about potential poor outcomes for babies when cannabis is used in pregnancy,” said lead author of the study, Lyndsay Avalos, PhD, MPH, a research scientist with the Kaiser Permanente Division of Research, in a statement.
“Our analysis adds new concerns about the potential for preterm birth and NICU admission, which are associated with immediate, highly stressful situations for the family as well as long-term adverse outcomes for the child,” she added.
For the study, the researchers included healthcare data from 364, 924 mothers and infants. In utero cannabis exposure was defined as self-reported use and frequency since becoming pregnant and/ or urine toxicology tests for cannabis during pregnancy.
Among the infants, 22, 624 (6.2%) were exposed to cannabis in the womb. Ultimately, the researchers found that in utero exposure to cannabis was linked to an increased risk of low birth weight, small for gestational age, preterm birth (classified as being born under 37 weeks of pregnancy), and admission to a neonatal intensive care unit.
They further noted a suggestive link with early preterm birth (being born before 34 weeks of pregnancy), and no significant association with infant respiratory support. The risk of low birth weight and small for gestational age increased alongside frequency of prenatal cannabis use.
The findings align with previous research that suggests a link between prenatal cannabis use and low birthweight babies. They also align with recommendations from the American College of Obstetricians and Gynecologists (ACOG) that discourage cannabis use among pregnant women and those contemplating pregnancy.
Sources: American Journal of Obstetrics and Gynecology, Kaiser Permanente Division of Research, EurekAlert