UC Riverside-led study suggests a possible link between vaping and difficulty conceiving in women

Vanillin, a common flavoring chemical in e-cigarettes, may disrupt the normal development of embryos in pregnant women who vape, according to a UC Riverside-led study.

The finding, published today in Human Reproduction, explains how vaping may be linked to women having difficulty conceiving and to miscarriages.

The researchers investigated human embryonic stem cells — which are similar to those in human embryos at three weeks old — in a series of laboratory tests. They caution that, as their findings are from a laboratory study, they cannot decisively establish that the same effects would be seen in women and their embryos.

“There is little understanding of how vaping can affect developing embryos in pregnant women who use electronic cigarettes,” said Prue Talbot, a professor of the graduate division in the Department of Molecular Cell & Systems Biology at UCR, who led the study. “We undertook this study to determine if vanillin, a flavor chemical often used in e-cigarettes at high concentrations, could adversely affect the development of young embryos in humans.”

Talbot and her team wanted to understand how chemicals in vape aerosols may affect young human embryos and identify the type of harm that could occur.

“We focused on vanillin because it is frequently used in e-cigarette fluids, it is often used at high concentrations, and because we knew that embryonic cells had a channel called TRPV4 on their surfaces that would likely bind with vanillin,” Talbot said.

Talbot and coauthor Shabnam Etemadi, a stem cell biologist and computational scientist at UCR, exposed human embryonic stem cells in dishes in the laboratory to different concentrations of vanillin: nanomolar (low) concentrations, or micromolar (high) concentrations. They also exposed the stem cells to a TRPV4 antagonist (a substance that inhibits vanillin binding to TRPV4); an antibody that blocks the function of TRPV4; or vanillin combined with either the antagonist or the antibody.

Embryonic stem cells have the potential to differentiate into any type of cell. In normal embryonic development, they form three cell types: endoderm, ectoderm and mesoderm.

“We found that micromolar concentrations tended to kill the cells,” Talbot said. “Nanomolar concentrations caused cells to lose pluripotency, which is the ability to develop into all cell types. Vanillin also caused the stem cells to differentiate into endoderm, rather than ectoderm or mesoderm. The endoderm is an embryonic tissue that gives rise to the lining of the gut and respiratory tissues. These changes are potentially very serious and could prevent normal development of embryos.”

More information: https://news.ucr.edu/articles/2026/08/12/vanillin-flavoring-e-cigarettes-disrupts-human-embryonic-stem-cell-development

About UC Riverside

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California’s diverse culture, UCR’s enrollment is more than 26,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual impact of more than $2.7 billion on the U.S. economy. To learn more, visit www.ucr.edu.