How E-Cigarette Exposure During Pregnancy May Reshape Fetal Lung Immunity

Researchers are investigating how prenatal e-cigarette exposure could alter fetal lung immunity, potentially affecting how newborns respond to respiratory viral infections. A newly funded five-year study will examine how chemicals and flavouring components found in e-cigarette aerosols influence the developing fetal lung and whether those changes could persist after birth.

The research, supported by a $2.4 million National Institutes of Health grant, comes as scientists continue to investigate the health effects of vaping during pregnancy. The project will focus not only on nicotine but also on acids, bases, salts and flavour-related components used in newer e-cigarette products.

Early laboratory findings from the research team suggest that prenatal exposure may interfere with important antiviral immune pathways in the developing lung. The effects also appear to differ between male and female offspring, raising questions about whether biological sex could influence how the developing respiratory system responds to vaping exposure.

However, it is important to distinguish between what researchers have observed in experimental models and what has been established in human pregnancies. The new project is designed to investigate these mechanisms further; it does not yet prove that vaping during pregnancy causes respiratory viral infections in newborns.

Why Researchers Are Studying Vaping During Pregnancy

E-cigarettes are sometimes perceived as less harmful than conventional cigarettes because they do not burn tobacco. But “less harmful than smoking” does not mean harmless, particularly during pregnancy.

Most e-cigarettes contain nicotine, and the aerosol can contain other chemicals, flavouring substances, ultrafine particles and metals. The composition can vary substantially between products, making it difficult to predict the biological effects of every formulation.

The Centers for Disease Control and Prevention states that using any tobacco product, including e-cigarettes, is not safe during pregnancy. Nicotine can cross the placenta and can harm the developing fetal brain and lungs. 0

The American College of Obstetricians and Gynecologists has similarly noted concerns about nicotine exposure, flavouring chemicals and other substances generated by electronic nicotine-delivery systems. It recommends that pregnant women be advised to discontinue e-cigarette and vaping-product use. 1

Against this background, scientists are now asking a more specific question: Could exposure during pregnancy change the way a baby’s developing lungs are programmed to respond to infection after birth?

New $2.4 Million Study Will Examine Fetal Lung Immunity

Researchers at Wayne State University School of Medicine’s C.S. Mott Center for Human Growth and Development have received a five-year, $2.4 million NIH-funded grant to investigate the effects of e-cigarette components and flavours during pregnancy. The study will examine fetal respiratory immune development and the potential susceptibility of offspring to respiratory viral infections. 2

The project is being led by Dr Jayanth Ramadoss, professor of Obstetrics and Gynecology and director of the Pregnancy and Environment Division at the C.S. Mott Center, and Dr Marta Rodriguez-Garcia, associate professor of Biochemistry, Microbiology and Immunology at Wayne State University School of Medicine. 3

Rather than treating e-cigarette exposure as a single substance, the researchers will investigate different components used in modern vaping products. This is important because the aerosol inhaled by a pregnant person is a complex mixture rather than simply nicotine.

What Happens to the Fetal Lung’s Immune System?

The lungs do more than exchange oxygen. They also contain a sophisticated immune system designed to detect and respond to pathogens entering the respiratory tract.

During fetal development, the lung undergoes major structural and biological changes. Immune cells and signalling networks are also established during this period, helping prepare the respiratory system for the transition from the protected environment of the womb to exposure to microbes after birth.

Researchers are particularly interested in whether e-cigarette exposure can alter this developmental process.

Preliminary experimental findings suggest that prenatal e-cigarette exposure can affect several components of innate immunity, including pathways involved in recognising viruses and initiating antiviral responses.

These findings are consistent with earlier experimental work from the research team. A 2026 study presented in the Journal of Animal Science reported sex-specific changes in immune-related genes and innate immune-cell populations in fetal lungs following e-cigarette exposure in a pregnant rat model. The researchers reported changes involving neutrophils, viral-sensing pathways and type I interferon signalling. 4

Why Interferon Signalling Matters

One of the most important areas being investigated is the type I interferon pathway.

Interferons are proteins that form an important part of the body’s early defence against viral infections. When cells detect signs of a virus, antiviral signalling pathways can trigger the production of interferons and activate genes that help limit viral replication and coordinate immune responses.

If these pathways are disrupted during development, researchers want to know whether the consequences could extend into the newborn period.

The preliminary findings suggest that prenatal e-cigarette exposure may alter viral-sensing mechanisms and type I interferon signalling in fetal lung tissue. However, these observations come primarily from experimental models, and researchers still need to determine how closely they translate to human pregnancy.

Neutrophils, Macrophages and Other Immune Cells Under Study

The new research will examine several cell populations involved in lung immunity, including:

• Neutrophils: immune cells involved in rapid responses to infection and inflammation.
• Macrophages: cells that help recognise and remove pathogens and cellular debris.
• Natural killer cells: immune cells capable of recognising and destroying certain infected or abnormal cells.
• Alveolar epithelial cells: specialised lung cells that form part of the respiratory barrier and participate in immune signalling.

Understanding how these cells communicate could help researchers determine whether prenatal exposure changes the lung’s ability to mount an appropriate response when a newborn encounters a respiratory virus.

Could Prenatal Vaping Increase Newborn Vulnerability to Viral Infections?

This is one of the central questions of the new study.

Preliminary laboratory findings indicate that offspring exposed to e-cigarette components before birth may show altered antiviral responses and increased susceptibility to respiratory viral infection in experimental models.

Earlier work from the Wayne State research group reported sex-specific changes in fetal lung immunity and observed enhanced susceptibility to neonatal viral infection in e-cigarette-exposed animals. 5

However, these findings should not be interpreted as proof that a baby born to someone who used an e-cigarette during pregnancy will develop viral infections. Animal studies are valuable for identifying biological mechanisms, but they cannot automatically establish the magnitude of risk in humans.

The new five-year study is intended to provide more detailed evidence about how exposure changes immune development and whether those changes have meaningful consequences after birth.

Why Male and Female Fetuses May Respond Differently

Another distinctive part of the research is its focus on biological sex.

Preliminary experiments suggest that male and female fetal lungs may respond differently to prenatal e-cigarette exposure. Researchers have observed differences in immune-related gene activity and immune-cell populations between male and female offspring.

This phenomenon is known as sexual dimorphism, meaning that biological responses can differ according to sex.

The finding is potentially important because respiratory diseases do not always affect males and females in exactly the same way. If prenatal environmental exposures influence immune development differently in male and female fetuses, the resulting health effects could also vary.

Researchers therefore plan to investigate biological sex as a possible determinant of fetal immune programming rather than treating all offspring as a single group.

Advanced Technology Will Map Immune Changes

The project will use several advanced techniques to understand how e-cigarette exposure changes the developing lung.

Spectral flow cytometry will allow researchers to examine multiple characteristics of individual immune cells simultaneously. This can help determine whether prenatal exposure changes the abundance or characteristics of specific immune-cell populations.

Confocal imaging will provide detailed visual information about cells and tissues, helping researchers understand where specific changes occur within the developing lung.

The team will also use single-cell RNA sequencing to examine gene activity at the level of individual cells. Instead of looking only at the average gene expression of an entire lung, this approach can reveal which specific cell populations are changing their behaviour.

Researchers will then use computational modelling and machine-learning and deep-learning approaches to identify affected gene networks and signalling pathways.

This combination could help connect the dots between exposure, molecular changes, immune-cell behaviour and potential susceptibility to infection.

Could Interferon Beta Become a Future Intervention?

One of the study’s most forward-looking objectives is to investigate whether interferon beta could help restore antiviral responses after prenatal exposure.

Researchers will test whether postnatal interferon beta treatment can correct disrupted antiviral pathways and gene networks in newborn experimental models exposed to e-cigarette components before birth.

This is an experimental research question, not an established treatment recommendation for infants exposed to vaping during pregnancy.

The significance lies in the possibility of identifying a biological pathway that could potentially be modified after birth. If researchers can determine which immune mechanisms are disrupted and whether they can be restored, it could provide clues for future studies aimed at protecting vulnerable newborns.

Any potential treatment would require extensive testing for safety, effectiveness, dosing and appropriate patient selection before it could be considered for clinical use.

What Earlier Research Already Suggests About Vaping and Lung Development

The new research builds on a growing body of experimental evidence suggesting that e-cigarette exposure can affect developing respiratory systems.

A 2026 experimental study in pregnant mice found that e-cigarette exposure was associated with oxidative imbalance, epithelial changes and immune dysregulation in maternal lung tissue. The researchers reported that conventional secondhand smoke produced stronger inflammatory effects in their model, but e-cigarette exposure still altered pulmonary homeostasis. 6

Other experimental studies have examined the effects of e-cigarette aerosols on developing lungs. Research using embryonic chick lung tissue, for example, found impaired lung growth and inflammatory responses after exposure to e-cigarette aerosol, although the effects were less pronounced than those produced by conventional cigarette smoke in that experimental system. 7

These findings do not establish an identical risk in humans, but together they provide a biological reason for continued investigation.

E-Cigarettes Are Not Considered Safe During Pregnancy

For pregnant people, one message is already clear even while scientists continue to investigate the precise mechanisms: e-cigarette use is not considered safe during pregnancy.

The CDC notes that most e-cigarettes contain nicotine, which is toxic to the developing fetus and can damage developing brain and lung tissue. It also states that e-cigarette use during pregnancy has been associated with outcomes including low birth weight and preterm birth. 8

MotherToBaby, an evidence-based teratology information service, also advises against e-cigarette use during pregnancy and notes that products can contain nicotine, solvents, flavourings, metals and other potentially harmful substances. 9

The challenge is that the scientific evidence is still evolving, particularly regarding the long-term effects of specific vaping formulations and their influence on infant immune development.

Why “Safer Than Cigarettes” Can Be a Misleading Message

One of the biggest difficulties in communicating about vaping during pregnancy is the tendency to frame the issue as a simple comparison with conventional cigarettes.

Combustible tobacco smoke contains thousands of chemicals and is firmly established as harmful during pregnancy. But an e-cigarette aerosol is not simply harmless vapour. It can contain nicotine and other substances whose concentrations and biological effects vary between devices and liquids.

The scientific question therefore should not be only whether vaping is safer than smoking. For pregnancy, the more relevant question is whether exposing a developing fetus to e-cigarette aerosol is safe.

Current evidence does not support considering vaping a safe option during pregnancy.

What This New Research Could Tell Scientists

The five-year project could help answer several unresolved questions about prenatal e-cigarette exposure.

• Which e-cigarette components have the strongest effects on fetal lung immunity?
• Does exposure alter antiviral signalling permanently or only temporarily?
• Which immune-cell populations are most affected?
• Why do male and female fetal lungs appear to respond differently?
• Do molecular changes translate into greater susceptibility to respiratory viruses after birth?
• Can disrupted antiviral pathways be restored after birth?
• Could specific biomarkers identify newborns who are particularly vulnerable?

Answering these questions could help researchers move from simply observing associations to understanding the biological mechanisms behind them.

The Human Evidence Gap Remains Important

Despite growing experimental evidence, researchers still face an important limitation: much of the detailed mechanistic work on fetal lung immunity comes from animal or laboratory models.

That distinction matters. A biological effect observed in a mouse or rat does not automatically mean that the same effect occurs at the same magnitude in humans.

Human pregnancies also involve differences in vaping patterns, nicotine exposure, product formulations, maternal health, diet, genetics, concurrent cigarette smoking and environmental exposures.

Consequently, the new research should be viewed as an effort to understand potential mechanisms and generate evidence that can eventually be tested in human populations.

Bottom Line

Prenatal e-cigarette exposure may alter the developing immune environment of the fetal lung, according to preliminary experimental findings, with potential effects on antiviral signalling and susceptibility to respiratory infection.

The newly funded $2.4 million, five-year study will investigate these effects in greater detail, including the roles of neutrophils, macrophages, natural killer cells, epithelial cells and type I interferon pathways. Researchers will also examine why male and female offspring may respond differently and whether interferon beta could restore disrupted antiviral responses after birth. 10

But the research is still ongoing. It does not establish that prenatal vaping causes respiratory viral infections in human newborns, nor does it establish interferon beta as a treatment.

What is already well supported by public-health guidance is that e-cigarettes should not be considered safe during pregnancy. For anyone who is pregnant and currently vaping or using nicotine products, discussing cessation with an obstetrician, doctor or other qualified healthcare professional is the appropriate next step.

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