Summary: A meta-analysis of 57 previous studies with over 12 million infants reveals that prenatal exposure to cannabis increases the risk of preterm birth, low birth weight, and the need for neonatal intensive care unit (NICU) admission.
However, the study did not find a higher risk of birth defects or infant mortality within one year, including sudden unexpected infant death. THC, the primary psychoactive component of cannabis, can cross the placenta, affecting fetal development.
This research highlights the importance of understanding the impact of maternal cannabis use during pregnancy on infant health.
Prenatal cannabis exposure is associated with a 1.5 times higher risk of preterm delivery, more than twice the risk of low birth weight, and a greater than twofold increase in NICU admission.
The study synthesizes data from 57 prior studies with over 12 million infant participants, including more than 100,000 exposed to cannabis.
The research spans studies published from 1984 to 2023, encompassing various countries.
Source: Society for the Study of Addiction
Infants prenatally exposed to cannabis are more likely to be born preterm, have a low birth weight, and require neonatal intensive care unit (NICU) care than infants without prenatal cannabis exposure, according to a study published today in the scientific journal Addiction.
However, cannabis-exposed infants are not at greater risk of birth defects or death within one year, including sudden unexpected infant death.
First author Ms. Maryam Sorkhou comments, “The global increase in cannabis use among women of reproductive age also extends to pregnant women. 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.”
This meta-analysis (a synthesis of past studies) pooled the results of 57 prior studies with a total of 12,901,376 infant participants, 102,835 of them exposed to cannabis.
Twenty of the studies measured the association between intrauterine cannabis exposure and risk of preterm delivery. In these, the combined results show that mothers using cannabis were over one and a half times more likely to have a preterm delivery compared with mothers not using cannabis during pregnancy.
Eighteen of the studies measured the risk of low birth weight. In these, the combined results show that mothers using cannabis during pregnancy were more than twice as likely to have a low-birth-weight baby compared with mothers not using cannabis during pregnancy.
Ten of the studies measured the risk of requiring NICU admission. In these, the combined results show that newborns with intrauterine cannabis exposure were more than twice as likely to require NICU admission than nonexposed newborns.
The studies included in this meta-analysis were published between 1984 and 2023 in a broad range of countries.