Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function

Abstract

ImportanceCannabis use is increasing among reproductive-age individuals and the risks associated with cannabis exposure during pregnancy remain uncertain.ObjectiveTo evaluate the association between maternal cannabis use and adverse pregnancy outcomes known to be related to placental function.Design, Setting, and ParticipantsAncillary analysis of nulliparous individuals treated at 8 US medical centers with stored urine samples and abstracted pregnancy outcome data available. Participants in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort were recruited from 2010 through 2013; the drug assays and analyses for this ancillary project were completed from June 2020 through April 2023.ExposureCannabis exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol using frozen stored urine samples from study visits during the pregnancy gestational age windows of 6 weeks and 0 days to 13 weeks and 6 days (visit 1); 16 weeks and 0 days to 21 weeks and 6 days (visit 2); and 22 weeks and 0 days to 29 weeks and 6 days (visit 3). Positive results were confirmed with liquid chromatography tandem mass spectrometry. The timing of cannabis exposure was defined as only during the first trimester or ongoing exposure beyond the first trimester.Main Outcome and MeasureThe dichotomous primary composite outcome included small-for-gestational-age birth, medically indicated preterm birth, stillbirth, or hypertensive disorders of pregnancy ascertained by medical record abstraction by trained perinatal research staff with adjudication of outcomes by site investigators.ResultsOf 10 038 participants, 9257 were eligible for this analysis. Of the 610 participants (6.6%) with cannabis use, 32.4% (n = 197) had cannabis exposure only during the first trimester and 67.6% (n = 413) had ongoing exposure beyond the first trimester. Cannabis exposure was associated with the primary composite outcome (25.9% in the cannabis exposure group vs 17.4% in the no exposure group; adjusted relative risk, 1.27 [95% CI, 1.07-1.49]) in the propensity score–weighted analyses after adjustment for sociodemographic characteristics, body mass index, medical comorbidities, and active nicotine use ascertained via urine cotinine assays. In a 3-category cannabis exposure model (no exposure, exposure only during the first trimester, or ongoing exposure), cannabis use during the first trimester only was not associated with the primary composite outcome; however, ongoing cannabis use was associated with the primary composite outcome (adjusted relative risk, 1.32 [95% CI, 1.09-1.60]).Conclusions and RelevanceIn this multicenter cohort, maternal cannabis use ascertained by biological sampling was associated with adverse pregnancy outcomes related to placental dysfunction.

Perinatal Impacts of Cannabis and Nicotine: An Analysis of the Cannabis Use During Development and Early Life Study

“…For our primary outcome of interest, SGA, initial analyses indicated a higher risk of SGA in PCU patients, particularly in those using cannabis at least twice a month for two or more trimesters, consistent with some prior studies. 16 However, after adjusting for confounders, including cotinine, there were no statistically significant differences in neonatal outcomes between PCU and control patients, which has also been previously demonstrated in the literature. 17 It is possible that this finding represents a type 2 error related to sample size, since the point estimate of our aRR (Table 3; aRR=1.61 [95% C.I.…”

“…1.08 – 2.14]) with a larger sample size. 16 Similarly, when comparing SGA rates between high PCU, low PCU, and controls, there were no significant differences once accounting for ADI. In contrast, analyses comparing SGA across PCU+c and controls demonstrated that neonates exposed to both cannabis and nicotine had significantly higher risk of SGA than both those exposed to cannabis alone and to controls, with no difference between PCU-c neonates and controls.…”

Racial Disparities in Newborn Drug Testing After Implementation of Question-Based Screening for Prenatal Substance Use

“…23 Considering the substantial increase in cannabis use among pregnant people, the risk of adverse pregnancy outcomes, and the possible effect on neurobehavioral outcomes, these results support the need to focus on treatment and avoid unnecessary punitive reporting to child protective services. 27,28…”

“…23 Considering the substantial increase in cannabis use among pregnant people, the risk of adverse pregnancy outcomes, and the possible effect on neurobehavioral outcomes, these results support the need to focus on treatment and avoid unnecessary punitive reporting to child protective services. 27,28 Limitations of this study include the absence of data to assess drug screening practices of pregnant individuals who delivered without prenatal care at our institution. We cannot fully describe clinician approach to substance use screening and treatment before implementation of universal screening.…”

The unseen patient: competing priorities between patients and providers when cannabis is used in pregnancy, a qualitative study

“…The American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) ( 15 ) advise against cannabis use during pregnancy because there is convincing evidence from observational studies that people who use cannabis during pregnancy are more likely to give birth to babies that are small for their gestational age and have a low birth weight ( 16 ). Specific cannabinoids present in cannabis can be effective for multiple sclerosis and chronic pain treatment ( 16 ) but it is likely that in utero exposure to cannabis may produce negative health effects ( 17 , 18 ). However, there are limitations to the conclusiveness of the current body of evidence ( 19 ).…”