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Cannabis Use Was an Independent Predictor of Prenatal Anxiety in 54,000 Nova Scotia Pregnancies

Retrospective CohortStrong evidence
The takeaway

Among nearly 54,000 first-time pregnancies in Nova Scotia over two decades, cannabis use was an independent predictor of prenatal anxiety, which rose dramatically from under 5% to over 20%.

Prenatal care providers, midwives, public health researchers studying maternal mental health trends.

Prenatal anxiety rose from <5% to >20%

What the researchers found

In 53,852 first-time pregnancies in Nova Scotia (2004-2023), reported prenatal anxiety prevalence was 8.9% overall but rose from under 5% to over 20% over the study period. Cannabis use was an independent predictor of prenatal anxiety in multivariable analysis, alongside younger or older age, being unpartnered, lower education, higher BMI, and smoking. These factors collectively explained 17.5% of variance.

Why it matters

The dramatic rise in reported prenatal anxiety over two decades (from under 5% to over 20%) is itself concerning. The identification of cannabis use as an independent predictor, after controlling for other risk factors, adds important information for prenatal screening and suggests cannabis use should be assessed as part of comprehensive anxiety screening during pregnancy.

The numbers in context

53,852 first pregnancies. Overall anxiety prevalence: 8.9%. Rose from <5% to >20% over 2004-2023. Cannabis use was an independent predictor. Model explained 17.5% of variance.

How the study worked

Retrospective cohort study using the Nova Scotia Atlee Prenatal Database of 53,852 primigravid persons with singleton pregnancies (2004-2023). Multivariable analysis examined birth year group, age, partner status, education, pre-pregnancy BMI, smoking, and cannabis use as predictors of reported prenatal anxiety.

What this study cannot tell us

Retrospective database study cannot determine causation. Rising anxiety rates may partly reflect increased recognition and reporting rather than true increases. Cannabis use was self-reported and likely underestimated. Cannot distinguish between recreational and self-medicating use. Only first-time pregnancies included.

How to read the evidence

Strong: very large population-based cohort (N=53,852) spanning two decades with multivariable adjustment, though self-reported measures and observational design limit causal conclusions.

When this study was published

2025 study (data from 2004-2023)

The bigger picture

Whether cannabis use causes prenatal anxiety or whether anxious individuals are more likely to use cannabis remains unclear from this observational design. However, the association is clinically relevant regardless of direction: pregnant individuals who use cannabis should be screened for anxiety, and those with anxiety should be asked about cannabis use.

Questions still open

  • Are anxious pregnant individuals using cannabis to self-medicate, or does cannabis worsen prenatal anxiety? Would the association hold with biomarker-confirmed cannabis exposure? How much of the anxiety increase reflects better screening versus actual rising rates?

Common questions

Does cannabis use during pregnancy cause anxiety?
Cannabis use was an independent predictor of prenatal anxiety in this large study, but the design cannot determine whether cannabis caused anxiety or anxious individuals were more likely to use cannabis.
Is prenatal anxiety becoming more common?
In Nova Scotia, reported prenatal anxiety in first-time mothers rose from under 5% to over 20% between 2004 and 2023, though some of this increase likely reflects improved recognition and screening.

Read the original research

The Prevalence and Predictors of Reported Prenatal Anxiety Among Primigravid Individuals in Nova Scotia.

Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC, 47(12), 103162

Citation

Ramia, Jessica; Piccinini-Vallis, Helena. (2025). The Prevalence and Predictors of Reported Prenatal Anxiety Among Primigravid Individuals in Nova Scotia.. Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC, 47(12), 103162. https://doi.org/10.1016/j.jogc.2025.103162

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