Smoking and vaping during pregnancy: the risks, and the help that works

What it does

Smoking in pregnancy narrows the blood vessels supplying the placenta and fills the blood with carbon monoxide, which displaces oxygen. The baby gets less of both food and oxygen for as long as it continues.

The consequences are well established: low birth weight and growth restriction, preterm birth, miscarriage, placental abruption and placenta praevia, stillbirth, and an increased risk of sudden infant death after the birth. There is also a raised risk of cleft lip and palate.

It is dose-related — fewer cigarettes is genuinely better than more — but there is no level that has been shown to be safe.

Bidis, hookah and shisha are not milder. Bidis deliver more carbon monoxide and nicotine than filtered cigarettes, and an hour of hookah exposes a person to far more smoke than a single cigarette.

Smokeless tobacco — gutkha, khaini, zarda, paan masala with tobacco, and betel quid — is used by a large number of Indian women, often without being thought of as smoking at all. It carries its own well-documented risks in pregnancy including low birth weight and stillbirth, and it is a major cause of oral cancer.

Vaping and e-cigarettes

E-cigarettes are banned in India under the Prohibition of Electronic Cigarettes Act 2019 — production, import, sale and advertising are all illegal, though possession for personal use is not the offence people assume it is.

They are not safe in pregnancy. Nicotine itself is the substance that restricts blood flow to the placenta and affects the developing brain, and vaping delivers nicotine efficiently.

Vapes also deliver flavourings, propylene glycol and metals, and the long-term effects of inhaling those in pregnancy are simply not known.

Vaping is less harmful than smoking for an adult who has switched completely — that is the basis of harm-reduction advice in some countries — but 'less harmful than smoking' is not the same as safe, and in pregnancy the goal is nicotine-free.

If you are currently vaping and it is the only thing keeping you off cigarettes, say so plainly to your obstetrician. That is a manageable situation and it needs a plan, not a lecture.

Quitting helps at every stage

This is the part that matters most. Stopping in the first trimester brings the risk of low birth weight close to that of someone who never smoked. Stopping before about 15 weeks removes most of the excess risk of preterm birth and growth restriction.

Stopping later still helps. Even in the third trimester, the baby's oxygen supply improves within days, and growth in the remaining weeks improves.

Carbon monoxide clears from the blood within about a day of the last cigarette.

And quitting protects after the birth too: the risk of sudden infant death, chest infections, asthma and ear infections in the baby all fall.

So there is no point in a pregnancy at which it is too late to be worth doing, and anyone who tells you otherwise is wrong.

India's National Tobacco Quitline is free on 1800-11-2356, and the government mCessation programme sends support by SMS. Your obstetrician can also refer you to a tobacco cessation centre — there are hundreds attached to hospitals across India, and they are free.

When to see a doctor

Tell your obstetrician that you smoke, vape or use tobacco. This is the single most useful thing on this page. Doctors need it to interpret growth scans, and you will be offered extra monitoring rather than judgement in most units.

Ask specifically about: nicotine replacement therapy in pregnancy, which is used under medical supervision and is considerably safer than continuing to smoke; growth scans; and referral to a cessation service.

Go to hospital immediately for: any bleeding, severe abdominal pain, a hard painful uterus, waters breaking, or reduced or changed fetal movements. Smokers are at higher risk of abruption and of growth restriction, and reduced movement is never something to sleep on. Call 108 if travel is difficult.

This article is general information, not medical advice, and is no substitute for personal medical advice. It has not been reviewed by an obstetrician or a cessation specialist.

Frequently asked questions

Q: Is cutting down enough? — Better than not cutting down, and not as good as stopping. Many people who cut down smoke each remaining cigarette more deeply, which reduces the benefit.

Q: Is it too late at 30 weeks? — No. The baby's oxygen supply improves within days and growth in the final weeks improves.

Q: Is nicotine gum safe in pregnancy? — It is used in pregnancy under medical supervision, and is regarded as considerably safer than smoking because it removes the carbon monoxide and the tar. Ask your obstetrician rather than buying it yourself.

Q: My husband smokes but I don't. — Second-hand smoke affects the pregnancy too, with a measurable effect on birth weight. Our page on second-hand and third-hand smoke covers what actually reduces the exposure.