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Systematic review maps the prevalence of polysubstance use in US pregnancies

Systematic ReviewLow evidence
The takeaway

A systematic review found polysubstance use during pregnancy is understudied, with wide-ranging prevalence estimates and cannabis frequently appearing as a co-used substance alongside tobacco, alcohol, or opioids.

Prenatal care providers, maternal health researchers, and substance use screening program designers.

Cannabis frequently appeared in prenatal polysubstance use combinations

What the researchers found

Polysubstance use during pregnancy involved diverse combinations, with cannabis commonly appearing alongside other substances. Prevalence estimates varied widely depending on screening method and population studied.

Why it matters

Most prenatal substance use research focuses on single substances, but real-world use often involves combinations. Understanding polysubstance patterns is essential for accurate risk assessment and targeted interventions.

The numbers in context

Literature from 2009-2020 reviewed. Cannabis was a common component of prenatal polysubstance use patterns alongside tobacco, alcohol, opioids, and stimulants.

How the study worked

Systematic review following PRISMA guidelines. Searched four databases for articles published January 2009 to June 2020 reporting prenatal exposure to two or more substances in the US.

What this study cannot tell us

Heterogeneous study designs and exposure definitions across included studies. Prevalence estimates are highly sensitive to screening methods used. Many studies relied on self-report. Publication date cutoff (2020) may miss recent trends.

How to read the evidence

Systematic review of heterogeneous studies. Useful for mapping the landscape but limited by inconsistent methods across included studies.

When this study was published

Published 2023. Literature through June 2020.

The bigger picture

Isolating the effects of cannabis in pregnancy is nearly impossible when polysubstance use is common. Until research accounts for substance combinations rather than single exposures, risk estimates for individual substances remain uncertain.

Questions still open

  • How should prenatal screening protocols address polysubstance use rather than single substances? Do specific substance combinations carry higher risk than individual exposures?

Common questions

How common is using multiple substances during pregnancy?
Prevalence estimates varied widely across studies depending on how use was measured. The review found that polysubstance use is an underrecognized pattern in prenatal populations, with cannabis commonly appearing alongside tobacco, alcohol, or opioids.
Why does polysubstance use matter for pregnancy research?
When pregnant people use multiple substances, it becomes very difficult to attribute health effects to any single one. Most cannabis-pregnancy studies try to control for other substance use, but polysubstance patterns may create interactive effects that single-substance analyses miss.

Read the original research

Systematic Review: Polysubstance Prevalence Estimates Reported during Pregnancy, US, 2009-2020.

Maternal and child health journal, 27(3), 426-458

Citation

Tran, Emmy L; England, Lucinda J; Park, Youngjoo; Denny, Clark H; Kim, Shin Y. (2023). Systematic Review: Polysubstance Prevalence Estimates Reported during Pregnancy, US, 2009-2020.. Maternal and child health journal, 27(3), 426-458. https://doi.org/10.1007/s10995-023-03592-w

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