How Alcohol, Drugs, and Smoking Can Affect Your Pregnancy

By Erica Patino
Reviewed by Alyssa Quimby, M.D. , Susan Ko, Ph.D.
August 16, 2023
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When you find out you’re pregnant, it changes your whole life—and it can require a change in your lifestyle, too.

To protect the health of your growing baby, it’s important to avoid:

  • Drinking alcohol
  • Smoking cigarettes, vaping, and using other tobacco products
  • Using marijuana
  • Taking illegal drugs like cocaine, fentanyl, or heroin

It’s also important to talk to your doctor about any prescription medications you take, and whether or not they’re safe to take while you’re pregnant.

Here's how each of these substances can affect you and your baby, and the guidelines for each during pregnancy.

Alcohol During Pregnancy

When a pregnant person drinks alcohol, it gets passed to their unborn baby through the placenta and umbilical cord. This can put the baby’s health in danger.

“Drinking alcohol during pregnancy is linked to preterm birth [when the baby is born too soon], low birth weight, and fetal alcohol syndrome,” says Kimberly Langdon, M.D., a board-certified ob-gyn in Columbus, Ohio. Fetal alcohol syndrome leads to physical and mental problems after the child is born, according to the March of Dimes.

Some people, countries, and cultures may have different opinions about drinking during pregnancy. But it isn’t safe to drink any alcohol during pregnancy, according to the American College of Obstetricians and Gynecologists (ACOG). That includes beer, wine, hard seltzer, wine coolers, cocktails, or liquor. It’s advised to stop drinking as soon as you find out you’re pregnant.

If not drinking is hard for you, talk to your doctor. They can connect you to a detox program. You can also find an alcohol treatment facility at Call SAMHSA National Helpline at 800-662-HELP. And consider joining Alcoholics Anonymous; get more info at

Cigarette Smoking, Vaping, and Tobacco Use During Pregnancy

“Smoking lowers the amount of oxygen in your blood, which can limit your baby’s growth,” says Teresa Hoffman, M.D., a board-certified ob-gyn at Hoffman and Associates OB/GYN in Baltimore.

And the harmful chemicals in tobacco are passed to the baby when a pregnant person smokes or chews it. Nicotine is a chemical found in tobacco. It can cause permanent damage to a growing baby’s brain and lungs, according to ACOG. Smoking can lead to preterm birth or a baby that’s too small, which can lead to serious health problems.

It isn’t safe to smoke cigarettes at all during pregnancy. E-cigarettes usually contain nicotine too. So vaping isn’t considered safe during pregnancy either.

If you smoke, vape, or use other tobacco products, make a plan to quit right away.

It can be hard to quit cold turkey. So talk to your doctor. They may prescribe you nicotine patches or gum to help you stop. You can also call 800-QUIT-NOW to speak with a quit-smoking counselor or text MOM to 222888 to join the SmokefreeMOM text message program.

Marijuana During Pregnancy

“Babies can get high, like moms get high,” says Hoffman. More research is needed on exactly how marijuana affects pregnancy. But a 2020 study suggests that using marijuana during pregnancy is tied to delayed development in the child after they’re born.

No amount of marijuana during pregnancy or while breastfeeding is safe. That includes smoking, vaping, and using edibles.

Do not use marijuana to relieve nausea. If you get nauseous during your pregnancy, talk to your doctor. They may prescribe a medicine that will not harm your baby.

Talk to your doctor about how to quit using marijuana if it’s hard for you. You can also find a substance use treatment facility at Or call SAMHSA National Helpline at 800-662-HELP.

Illegal Drugs During Pregnancy

Illegal drugs like cocaine, fentanyl, and heroin are dangerous for you at any time. During pregnancy, they’re extremely dangerous for your unborn baby.

For example, cocaine can cause a placental abruption, a complication of the placenta, which can cause bleeding and miscarriage, says Langdon. Cocaine can also cause seizure or stroke for the pregnant person. Using substances like fentanyl and heroin during pregnancy can cause preterm birth, stillbirth, death of the pregnant person, and neonatal abstinence syndrome. This is when babies have to go through drug withdrawal for weeks after their birth.

No amount of any type of illegal drug is safe during pregnancy. Stop taking these drugs immediately if you’re pregnant or planning to become pregnant.

Discuss your drug use with your doctor right away. To treat heroin or fentanyl addiction, they may prescribe methadone or buprenorphine during pregnancy. For cocaine, they may connect you to a detox program.

You can also find a treatment facility at For additional help, call the SAMHSA National Helpline at 800-662-HELP.

Prescription Drugs During Pregnancy

Some prescription medications are safe to continue taking during pregnancy. Some are not. So don’t assume that what you’re taking is okay for your baby.

Certain prescription medications for blood pressure, seizures, and pain can be harmful to a growing baby, says Hoffman. Some medications for bipolar disorder and anxiety should be avoided too. Even some antibiotics and yeast infection medications are not safe.

Some medications can be harmful to stop suddenly, so it’s best to get medical advice for stopping anything. In some cases, medicine should be given at a gradually lower dose over time.

If you’re taking prescription medication, it’s best to talk to your doctor before you become pregnant. That way, you can come up with a plan for your medication during pregnancy.

If you weren’t able to discuss medication before getting pregnant, talk to your doctor as soon as possible. Tell them all the medications you take. That includes non-prescription items like supplements, too.

Your doctor will help you know which medications you can keep taking and which you should stop. They may be able to prescribe you a safer alternative while you’re pregnant.

It’s Important to Ask for Help

Be honest with your doctor about what type of substances you’re using. If your doctor doesn’t know, they can’t help you. And it’s crucial to stop taking harmful substances as soon as possible if you’re pregnant or thinking about getting pregnant.

If you’re worried about stopping a prescription medication, know that there are almost always alternative medications your doctor can prescribe you that will treat you while keeping your unborn baby safe.

While it can feel scary to quit something you’re used to or addicted to, know that you may have more strength than you realize—especially now that you’re pregnant.

“I used to smoke a pack a day. The day I found out I was pregnant, I never smoked again,” says Hoffman. “The reality is, there are things you do for your baby that you won't do for yourself.”

If this feels overwhelming or you don’t know where to start, consider working with an addiction counselor or therapist. Often, people need help handling issues that lead to their alcohol or substance use.

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