Prenatal cannabis use was associated with higher SARS-CoV-2 infection risk in California pregnancies | Research

The takeaway

Among 58,114 pregnancies in California, prenatal cannabis use was associated with increased risk of SARS-CoV-2 infection during pregnancy, possibly through immune modulation or behavioral factors.

OB/GYN providers, infectious disease specialists, and researchers studying cannabis immunological effects during pregnancy.

58,114 pregnancies; prenatal cannabis use linked to higher SARS-CoV-2 risk

What the researchers found

Prenatal cannabis use was significantly associated with higher risk of SARS-CoV-2 infection during pregnancy in a large California cohort. The association remained after adjusting for known confounders.

Why it matters

If cannabis use increases infection susceptibility during pregnancy, it represents an additional risk factor that prenatal care providers should consider, particularly during respiratory illness surges.

The numbers in context

58,114 pregnancies in California. Prenatal cannabis use associated with increased SARS-CoV-2 infection risk after adjusting for confounders.

How the study worked

Retrospective cohort study of 58,114 pregnancies in California. Cannabis use identified through prenatal screening. SARS-CoV-2 infection status determined from testing records. Adjusted for demographic and clinical confounders.

What this study cannot tell us

Retrospective design. Cannot confirm causation. Cannabis use measured at screening and may not reflect use throughout pregnancy. Behavioral confounders (social distancing compliance, testing frequency) difficult to fully control. Single geographic region during a specific pandemic wave.

How to read the evidence

Large retrospective cohort with adjusted analysis. Behavioral confounding and single-pandemic-wave context limit generalizability.

When this study was published

Published 2023.

The bigger picture

Cannabis has immunomodulatory properties, and respiratory effects of smoked cannabis could affect vulnerability to respiratory infections. This finding adds to concerns about cannabis use during pregnancy beyond fetal development effects.

Questions still open

Is the association driven by immune effects of cannabinoids or by behavioral correlates of cannabis use? Would non-smoked cannabis show the same association with respiratory infection risk?

Common questions

Does cannabis use during pregnancy increase COVID risk?

This large California study found an association between prenatal cannabis use and higher SARS-CoV-2 infection rates. However, it cannot prove cannabis caused the increased infection risk. Behavioral differences between cannabis users and non-users, rather than biological effects of cannabis, could explain the finding.

How might cannabis affect infection risk?

Cannabis has immunomodulatory properties that could theoretically affect susceptibility to infections. Additionally, smoking cannabis irritates respiratory tissue, potentially making airways more vulnerable. Social and behavioral factors associated with cannabis use may also influence exposure risk.

Read the original research

Association of cannabis use during pregnancy with severe acute respiratory syndrome coronavirus 2 infection: a retrospective cohort study.

Addiction (Abingdon, England), 118(2), 317-326

View on PubMed ↗Publisher’s paper ↗

Citation

Young-Wolff, Kelly C; Ray, G Thomas; Alexeeff, Stacey E; Benowitz, Neal; Adams, Sara R; Does, Monique B; Goler, Nancy; Ansley, Deborah; Conway, Amy; Avalos, Lyndsay A. (2023). Association of cannabis use during pregnancy with severe acute respiratory syndrome coronavirus 2 infection: a retrospective cohort study.. Addiction (Abingdon, England), 118(2), 317-326. https://doi.org/10.1111/add.16056