This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by Public Health England on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

There is strong scientific evidence that smoking during pregnancy increases the likelihood of miscarriage, certain birth defects, premature birth, and poor growth of the baby in the womb, which has been linked to certain health problems later in life. Pregnant women and women trying to conceive should ideally stop smoking. While it is better to have given up smoking before pregnancy, research shows that stopping smoking or cutting down significantly in early pregnancy can reduce the risk of the baby having some of the health problems linked to smoking. If you need help to stop smoking you should speak to your doctor or midwife.