E-cigarettes vs Nicotine Patches in Pregnancy: What the 2026 PREP Trial Means for UK Pregnant Smokers

Introduction

Quitting smoking in pregnancy delivers the clearest health benefits for babies and mothers. The 2026 PREP randomised controlled trial in the UK — which enrolled 1,140 pregnant smokers — directly compared e-cigarettes with nicotine patches. With 569 women assigned to e-cigarettes and 571 to nicotine patches, the trial provides timely data to help pregnant smokers and clinicians weigh options for quitting.

Feature-by-feature comparison

Effectiveness for stopping smoking

The PREP trial reported validated prolonged quit rates at end-of-pregnancy of 6.8% in the e-cigarette arm versus 4.4% in the patch arm (unadjusted). This suggests e-cigarettes may be more effective than patches for achieving abstinence in pregnancy, although absolute quit rates were modest. Factors that probably influence success include nicotine delivery, behavioural substitution (hand-to-mouth action), and how acceptable the product is to the individual.

Safety and pregnancy outcomes

Crucially, the PREP trial found that regular use of either nicotine replacement therapy (NRT — patches in this case) or e-cigarettes during pregnancy was not linked with increased adverse pregnancy outcomes. Moreover, women who became abstinent while using either method had higher birth weights than those who continued to smoke. While this is reassuring, it is important to remember that "not linked" is not the same as "proven entirely safe"; long-term evidence is still being collected.

Exposure to toxins

A UK biomarker study supports the harm-reduction message: pregnant women who vape had far lower levels of most toxins in their urine — levels broadly similar to women who never smoked — compared with those who continued to smoke. Lower toxicant exposure is biologically plausible because e-cigarettes do not burn tobacco, a major source of harmful combustion products.

Uptake and real-world use

In PREP, e-cigarette use was more common than NRT (47.3% vs 21.6%). This higher uptake may reflect palatability, convenience, or perceived effectiveness. For many smokers the behavioural aspects of vaping (inhalation, flavour, ritual) can help replace cigarettes in ways that patches do not.

Regulation and nicotine strength

An important generalisability caveat: PREP primarily involved refillable e-cigarettes with nicotine strengths limited by UK/EU regulations (around ≤20 mg/ml). That means the findings may not fully apply to modern high-nicotine pod systems commonly used elsewhere, which can deliver nicotine faster and at higher doses.

Pros and cons — e-cigarettes vs nicotine patches

E-cigarettes

• Pros: Higher uptake in PREP; modestly higher quit rates (6.8% vs 4.4%); behavioural substitution helps many smokers; biomarker data show large reductions in many toxins compared with continued smoking.
• Cons: Long-term safety data in pregnancy remain limited; product variety and unregulated devices/fluids (outside UK rules) complicate comparisons; some women may still prefer licensed, clinician-controlled options.

Nicotine patches (licensed NRT)

• Pros: Recommended first-line by the NHS and other UK bodies; well-studied formulations; clear dosing and licensing; PREP found no link with increased adverse pregnancy outcomes when used in pregnancy.
• Cons: Lower uptake in PREP and slightly lower quit rate in the trial; lacks the behavioural aspects of cigarette use (hand-to-mouth, inhalation), which can be important for some smokers.

What UK guidance says

The NHS and many UK organisations continue to recommend licensed NRT (patches, gum, inhalator) as first‑line smoking-cessation options in pregnancy. However, public-health groups including Action on Smoking and Health (ASH) and the Smoking in Pregnancy Challenge Group say vaping can be supported if it helps a pregnant woman remain smoke‑free. In practice this means clinicians should discuss options openly, prioritise quitting smoking entirely, and tailor support to the individual.

Practical advice and product considerations

If you're pregnant and trying to quit, discuss plans with your midwife, GP or stop-smoking service. Key practical points:

• Start with licensed NRT (patches ± short-acting forms like gum or the inhalator), as per NHS guidance.
• If NRT alone doesn't work and you are considering vaping, seek professional advice. If chosen, use products compliant with UK rules (nicotine ≤20 mg/ml) and avoid unregulated high-strength systems.
• Consider real-world product features: refillable setups can allow nicotine dose adjustment and flavours that help adherence; for those who prefer disposable simplicity, some users opt for those too.

For example, those exploring refillable e-liquid options might look at nicotine salt longfills combined with nicotine shots to reach the lawful strength, such as Crystalize Bar Salts 120ml longfill (with nicotine shots) — but always check nicotine concentration and legality, and speak to a clinician first. For smokers liking disposables, products like the iFresh 10000 puffs disposable or cartridge systems such as Ezee e-cigarette cartridges illustrate how varied devices are, though many available options are nicotine-free or different strengths — again, consult a professional.

Chewable or oral nicotine alternatives (not a substitute for licensed NRT without advice) exist too; for instance nicotine candy products exist, but their role in pregnancy should be discussed with clinicians and local stop-smoking services before use.

Recommendation — which is best for whom?

If you are pregnant and smoking, the single best action is to quit. NHS-recommended, licensed NRT remains the first-line option in the UK because of clear regulatory oversight and clinical familiarity.

• Choose NRT (patches ± short-acting forms) if: you want a clinician-recommended, well-studied option and prefer regulated dosing and simplicity.
• Consider e-cigarettes if: you have tried NRT and not quit, you find vaping substantially helps you avoid cigarettes, and you use UK-compliant devices and liquids — but only after discussing this with your midwife or GP.
• Always avoid smoking: PREP showed abstainers using either product had higher birth weights than those who continued to smoke — quitting smoking is the priority.

Conclusion

The 2026 PREP trial adds valuable, pragmatic data: e-cigarettes may offer a small advantage over patches for quitting in pregnancy and neither approach was linked with increased adverse pregnancy outcomes in the study. Biomarker evidence also indicates vaping greatly reduces exposure to many tobacco-related toxins compared with continued smoking. However, NHS guidance still recommends licensed NRT as first-line, and the findings from PREP mostly reflect refillable, lower‑strength e-cigarettes under UK regulations — so results may not apply to higher‑strength pod systems. Whatever your choice, talk to your healthcare team, focus on becoming and staying smokefree, and use the option that gives you the best chance of protecting your baby’s health.