Abstract
Importance
Following expansive legalization of cannabis in many parts of the United States, cannabis use in pregnancy has increased several fold. There is a pressing need to understand the maternal and neonatal outcomes associated with this exposure.
Objective
To quantify the maternal and neonatal outcomes of mothers using cannabis during pregnancy.
Data sources
We searched five databases for all relevant observational studies, from each database’s inception until March 1st 2024.
Study selection
Two reviewers separately screened the studies in duplicate. Our initial search yielded 5184 studies, of which 51 (0.98%) were included in our qualitative synthesis.
Data extraction and synthesis
Our study adhered to PRISMA guidelines and independent extraction by two researchers was utilized. We used a 95% confidence interval and the random effects model, as there was significant heterogeneity between studies.
Results
The 51 included studies yielded a total population of 7,920,383 pregnant women. Cannabis consumption was associated with increased risks of low birth weight (RR = 1.69,95% CI = (1.34,2.14),P < 0.0001), small for gestational age (RR = 1.79,95% CI = (1.52, 2.1),P < 0.00001), major anomalies (RR = 1.81,95% CI = (1.48, 2.23),P < 0.00001), decreased head circumference (MD = -0.34,95% CI = (-0.57,-0.11),P = 0.004), birth weight (MD = -177.81,95% CI = (-224.72,-130.91),P < 0.00001), birth length (MD = -0.87,95% CI = (-1.15,-0.59),P < 0.00001), gestational age (MD = -0.21,95% CI = (-0.35,-0.08),P = 0.002), NICU admission (RR = 1.55,95% CI = (1.36,1.78),P < 0.00001), perinatal mortality (RR = 1.72,95% CI = (1.09,2.71),P = 0.02), and preterm delivery (RR = 1.39,95% CI = (1.23,1.56),P < 0.00001). Cannabis use was also associated with a decreased risk of gestational diabetes in pregnancy (RR = 0.64,95% CI = (0.55,0.75),P < 0.00001).
Conclusions
Inclusion of the latest published data continues to show worse maternal and neonatal outcomes for mothers using cannabis in pregnancy.