Smoking and Fertility: How Cigarettes Affect Reproductive Health

Smoking affects fertility in both women and men, and pregnancy outcomes after that. The American Society for Reproductive Medicine's practice committee reviews the harmful effects of smoking on conception, the ovaries, sperm, early pregnancy and fertility-treatment outcomes, and WHO says quitting reduces the chances of impotence, difficulty getting pregnant, premature birth, low birth weight and miscarriage. Below, we give numbers only where a study or health body publishes them.

Effects on Female Fertility

Ovaries and Eggs

The ASRM committee opinion covers smoking's effects on the ovaries and on eggs. Many studies link smoking with an earlier menopause and lower ovarian reserve; we don't give a figure for how much earlier, because we couldn't check one against the full text.

Getting Pregnant

WHO lists difficulty getting pregnant among the harms quitting reduces. In fertility treatment, the effect has been measured directly: a meta-analysis found smokers having IVF or other assisted reproduction had about half the odds of a live birth per cycle (OR 0.54) and of a clinical pregnancy (OR 0.56) compared with non-smokers, and higher odds of miscarriage and ectopic pregnancy.

Miscarriage

A meta-analysis of 98 studies found that active smoking raised the risk of miscarriage by about 23%, and by about 32% when the smoking was during that pregnancy; risk rose about 1% for each cigarette smoked a day. Secondhand smoke during pregnancy was linked to about an 11% higher risk.

Effects During Pregnancy

The NHS says that stopping smoking in pregnancy reduces the risk of complications, stillbirth, premature birth, low birth weight and sudden infant death syndrome (SIDS). Cigarettes can restrict the oxygen supply to the baby — carbon monoxide crosses the placenta, and the UK Health Security Agency says its half-life in the unborn baby is up to 4 to 5 times longer than in the mother.

Effects on Male Fertility

Sperm

A meta-analysis of 20 studies and 5,865 men found smoking was associated with lower sperm count, lower motility and more abnormally shaped sperm, with bigger effects in moderate and heavy smokers and in men already having fertility problems.

Erectile Function

WHO lists impotence among the harms quitting reduces. The 2020 Surgeon General's report is more cautious about the evidence that quitting lowers erectile-dysfunction risk, calling it inadequate, so we don't promise a timeline.

How Quickly Does Fertility Recover After Quitting?

The honest answer is that timelines haven't been measured well. What's clear:

Men: sperm are made continuously, so new sperm are produced without smoke exposure from the day you stop. Fertility clinics commonly advise stopping at least three months before trying to conceive or starting treatment, to cover a full cycle of sperm production.
Women: the ASRM committee opinion recommends quitting before fertility treatment; eggs already lost don't come back, so the earlier you stop, the better.
Both: stopping reduces carbon monoxide and other chemicals in the body within days, which matters from the moment of conception.

If you're planning a pregnancy or fertility treatment, ask your GP or clinic for stop-smoking support now.

Quitting During Pregnancy

The NHS says the sooner you stop, the better — but even stopping in the last few weeks of pregnancy benefits you and your baby.

Medicines in pregnancy: the NHS says you can use NRT during pregnancy if it helps you stop and you can't stop without it, but stop-smoking tablets such as varenicline or bupropion are not recommended during pregnancy. Talk to your midwife or GP — they can prescribe NRT and refer you to a free stop-smoking adviser.

Secondhand smoke: the NHS says a partner's or housemate's smoke can reduce the baby's birthweight and raise the risk of SIDS, and the National Smokefree helpline (0300 123 1044) supports partners too.

FAQ

Does smoking affect chances of getting pregnant?

Yes. WHO lists difficulty getting pregnant among the harms quitting reduces, and in fertility treatment smokers had about half the odds of a live birth per cycle. In men, smoking is associated with lower sperm count and motility.

How long after quitting smoking does fertility improve?

It hasn't been timed precisely. For men, clinics commonly advise quitting at least three months before trying, to cover a sperm-production cycle. For women, the earlier the better. Either way, ask your GP or clinic for support to stop now.

Does smoking affect IVF success rates?

Yes. A meta-analysis found smokers had about half the odds of a live birth per treatment cycle compared with non-smokers, and higher odds of miscarriage. Fertility specialists recommend stopping before treatment.