Women with Severe Pregnancy Nausea Were More Likely to Report Marijuana Use During Pregnancy | Research

The takeaway

In a Hawaii population survey, women who reported severe nausea during pregnancy were 63% more likely to also report marijuana use during pregnancy.

Read this if you are pregnant or planning pregnancy and want to understand the research on marijuana and pregnancy nausea.

63% higher marijuana use during pregnancy among women with severe nausea (PR=1.63)

What the researchers found

Among 4,735 recently pregnant women in Hawaii, 6.0% reported marijuana use in the month before pregnancy and 2.6% reported use during pregnancy. Approximately 21.2% reported severe nausea during pregnancy.

Women who experienced severe nausea were significantly more likely to report marijuana use during pregnancy compared to those without severe nausea (3.7% vs. 2.3%; prevalence ratio 1.63, 95% CI: 1.08-2.44).

The study could not determine the direction of this relationship: women may have used marijuana to treat severe nausea, or marijuana use may have contributed to the nausea (as in cannabinoid hyperemesis syndrome), or both could have been driven by other factors.

Why it matters

Marijuana has been proposed as a treatment for severe pregnancy nausea (hyperemesis gravidarum), but this creates a clinical dilemma: cannabis use during pregnancy carries potential risks to fetal development. Understanding the relationship between marijuana use and pregnancy nausea is essential for clinical guidance.

The numbers in context

4,735 respondents. Marijuana use: 6.0% in month before pregnancy, 2.6% during pregnancy. Severe nausea: 21.2%. Women with severe nausea were 63% more likely to use marijuana during pregnancy (PR=1.63, 95% CI: 1.08-2.44).

How the study worked

This cross-sectional study used Hawaii Pregnancy Risk Assessment Monitoring System (PRAMS) data from 4,735 respondents, weighted to represent all pregnancies resulting in live births in Hawaii between 2009 and 2011. Self-reported marijuana use (before and during pregnancy) and severe nausea were assessed. Prevalence ratios and 95% confidence intervals were computed.

What this study cannot tell us

This was a cross-sectional study, so temporal relationships cannot be determined. Self-reported marijuana use during pregnancy is likely underreported due to social desirability and legal concerns. The study could not distinguish between marijuana use for nausea relief versus recreational use that happened to coincide with nausea. Severity of nausea was self-reported.

How to read the evidence

This is a cross-sectional population survey. It cannot establish whether marijuana use preceded, followed, or caused the nausea.

When this study was published

Published in 2014. Research on cannabis use during pregnancy and associated outcomes has expanded substantially since.

The bigger picture

The relationship between cannabis and nausea during pregnancy is complicated by two opposing phenomena: cannabis can relieve nausea (antiemetic effect), but chronic cannabis use can also cause severe nausea and vomiting (cannabinoid hyperemesis syndrome). This bidirectional relationship makes it difficult to give clear clinical guidance without more research.

Questions still open

Are women using marijuana specifically to treat pregnancy nausea? Does marijuana use during pregnancy worsen or contribute to nausea in some women? What are the fetal outcomes associated with marijuana use for pregnancy nausea?

Common questions

Is marijuana safe for treating pregnancy nausea?

The safety of marijuana during pregnancy has not been established. Major medical organizations advise against cannabis use during pregnancy due to potential risks to fetal development, including low birth weight and possible neurodevelopmental effects.

Could marijuana actually cause the nausea?

The authors note that cannabinoid hyperemesis syndrome, a condition causing severe nausea and vomiting in chronic cannabis users, is a complicating factor. Some women who use marijuana during pregnancy may actually be experiencing this syndrome rather than typical pregnancy nausea.

Read the original research

Marijuana use and maternal experiences of severe nausea during pregnancy in Hawai'i.

Hawai'i journal of medicine & public health : a journal of Asia Pacific Medicine & Public Health, 73(9), 283-7

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Citation

Roberson, Emily K; Patrick, Walter K; Hurwitz, Eric L. (2014). Marijuana use and maternal experiences of severe nausea during pregnancy in Hawai'i.. Hawai'i journal of medicine & public health : a journal of Asia Pacific Medicine & Public Health, 73(9), 283-7.