When a woman discovers she is pregnant, one of the first things she wants to know is if she should continue to smoke cigarettes or drink alcohol, as she has heard that they can be harmful to the baby. She probably already knows that she shouldn’t be doing drugs of any kind, anyway, but especially during pregnancy. So, why not? Why is smoking dangerous during pregnancy? Why is drinking alcohol dangerous for the fetus? And what kinds of drugs are harmful?


There are many harmful chemicals in cigarettes besides nicotine. There are over 4,000 toxic chemicals that can pass from the mother to her fetus. Nicotine itself restricts blood vessels, which means less oxygen and nutrients reach the baby. Nicotine damage to a fetus’ brain and lungs may also be permanent.

Electronic cigarettes (e-cigarettes) aren’t safe either, as they contain nicotine, plus flavoring and a propellant that may be unsafe for the developing baby.

Preterm birth (birth occurring before 37 weeks of pregnancy) is more likely to occur when a woman smokes during pregnancy. Babies who are born too early may not be fully developed and they are at increased risk of Sudden Infant Death Syndrome (SIDS). They are more likely to have colic and to develop asthma and childhood obesity.

Secondhand smoke (smoke that you can inhale of others’ cigarettes around you) increases the risk of a low birth weight baby…maybe as much as 20%. Infants who are exposed to secondhand smoke have an increased risk of SIDS. They are also more likely to have asthma attacks and ear infections.


Alcohol can interfere with a fetus’ normal growth and also cause birth defects. Physical, intellectual, behavioral, and learning disabilities can also develop and last a lifetime. Fetal Alcohol Syndrome (FAS) is the most severe disorder, which can cause growth problems, abnormal facial features, intellectual disabilities, and behavioral problems.

FAS usually develops when a woman drinks heavily during her pregnancy, but even lesser amounts can cause damage, not to mention the possibilities of alcohol-impaired accidents, including vehicular and home. It is best not to drink any alcohol during pregnancy.


The use of illegal substances such as heroin, cocaine, methamphetamines, and prescription narcotics (also known as opioids, which include oxycodone, hydromorphone, hydrocodone, and codeine) taken for a non-medical reason, is a widespread problem in the U.S. About 5% of women use illegal drugs during their pregnancy.

Using illegal drugs during early pregnancy can lead to birth defects and miscarriage. Later in the pregnancy they can cause preterm birth and fetal death. Babies born after illegal drug use usually need specialized care, and have an increased risk of medical and behavioral problems.

Marijuana, a so-called recreational drug, is associated with attention and behavioral problems in children and may increase the risk of stillbirth. Babies born after the mother has used marijuana are generally smaller and weigh less than other babies. Women who have prescription medical marijuana should talk with their obstetrician or other medical health provider about using alternative treatments that will be safe for the fetus.


Some prescription medications are safe to take, and others are not. Don’t stop taking your prescription medication, but talk to your health provider. If the medication you are taking is a risk, your obstetrician or health care professional may recommend switching to a safe drug while you are pregnant, or simply change the dosage.


Again, talk to your obstetrician or health care provider. Some medications, including herbal supplements, can cause problems during pregnancy.