Higher levels of alcohol use, including alcohol abuse, are unhealthy throughout life. In pregnancy, it is well established that birth defects can result from drinking alcohol, particularly during the first weeks of pregnancy (perhaps before women know they’re pregnant) when the vital organs of the embryo and fetus are developing. Risks of intellectual disability, miscarriage and low birth weight have also been linked to alcohol consumption during pregnancy. Fetal Alcohol Spectrum Disorder, including its most severe form, Fetal Alcohol Syndrome, are lifelong tragedies for affected children and their families. For this reason, if you are a heavy alcohol user or have a dependency, it is important to change your habits and get needed help before trying to become pregnant.

Less clear is our understanding of the impact of limited or moderate use of alcohol, both when planning pregnancy and during pregnancy. Because of uncertainty regarding effects of lesser amounts of alcohol, it would be wise to avoid alcohol once you begin to try to conceive.

Because of the damage that might be done to the developing fetus in the first few weeks of pregnancy – often before a woman realizes she’s pregnant – experts strongly recommend that women, their partners and any other smokers in the household stop smoking before the couple tries to conceive.

The smoke you inhale when you smoke and secondhand smoke from others increases the risk of having:

• Premature birth
• A low birth weight baby
• Premature rupture of membranes
• Problems with the placenta
• Miscarriage
• Stillbirth

Smoke also increases risk of the baby dying from Sudden Infant Death Syndrome (SIDS). Children who have been exposed to cigarette smoke before birth may be more likely to develop asthma, learning and behavioral problems and ear infections.

Smoking may also make it more difficult for you to conceive. If you can’t stop smoking before you become pregnant, we strongly urge you to stop as soon as you learn you are pregnant. The more you smoke, the greater the risks to your fetus. As soon as you stop smoking, even if you are already pregnant, the risks to your fetus decrease. If you cannot quit, reducing the amount you smoke and the exposure to secondhand smoke may lower your risks. Ask your health care provider for help with quitting smoking; there are many tools and supports available to help you quit. See the list of resources at the end of this page.

It is too early to know about shorter- and longer-term effects of e-cigarettes on fertility, pregnancy, the fetus/newborn and parents who use them. However, they contain nicotine, which is addictive and may prime the brain for other kinds of addictions and other potentially harmful substances. It would be wrong to assume that these are safe.

When it comes to illegal drugs or those used for recreational purposes, we strongly urge you to stop using them before trying to get pregnant.

Recreational street drugs have the potential to harm you and your fetus:

• Marijuana increases risk for miscarriage in animals. In humans, its use in pregnancy has been associated with babies with excess crying and trembling, increased risk of attention disorders, and poorer school performance.
• Cocaine use is associated with separation of the placenta before birth, preterm birth, low birth weight, and newborns experiencing withdrawal syndrome.
• Heroin and other narcotics can cause miscarriages, premature births and low birth weight in exposed babies. Most babies exposed to heroin before birth suffer from withdrawal symptoms at birth.
• PCP (“angel dust”) can lead to small babies and babies with poor control of their movements.
• LSD may lead to birth defects.
• Glue and solvent sniffing may cause low birth weight, bone problems, developmental delays and other problems in babies.
• Amphetamines (including methamphetamine, also known as speed, ice, crank and crystal meth) are powerful stimulants that may cause separation of the placenta before birth, preterm birth, low birth weight, damaged organs and emotional and learning problems in babies.
• Medical prescription drugs sold illegally for recreational use are potentially dangerous to the user. Commonly misused prescribed drugs include:
• Prescription opioids (including oxycodone, codeine, fentanyl, hydrocodone, hydromorphone) are addicting and can cause miscarriage, low birth weight and newborns experiencing withdrawal syndrome.
• Ketamine (“Special K”), a tranquilizer used on humans and animals, causes delirium, amnesia, depression and long-term memory problems.
• Rohypnol (“Roofie”), a powerful tranquilizer, is not prescribed in the United States but is illegally imported from other countries. It is often called a “date rape drug.”
• “Designer” drugs are now among the most popular recreational drugs. There have not been any long-term studies of these manufactured substances, but short-term studies and anecdotal data suggest they are dangerous and you should avoid them if you are considering getting pregnant. Designer drugs include:
• Ecstasy/Molly (MDMA) is a stimulant with a broad range of negative effects in users.
• GHB, also a so-called “date rape drug,” causes unconsciousness, seizures, severe respiratory depression and coma in women exposed to high dosages of the drug.
• GBL, a compound used to make GHB, can be used by itself and has effects similar to GHB.

The amount of data available on the effect of drugs on men varies depending on the type of drug, but here are a few things to keep in mind when it comes to a father’s behavior:

• Heavy drinking impairs sexual performance (a critical part of getting pregnant!).
• Sperm of men who have 3-4 drinks a day may become damaged, and their children may be born with low birth weight.
• Smoking can lower a man’s fertility, damage his sperm and make it more difficult for you to conceive.
• Drinking more than 700mg of caffeine a day (about five cups of regular coffee) may affect the health and/or survival rate of the fetus.

Pregnant and breastfeeding women have been expressly left out of studies examining possible benefits and harms of new drugs before they are marketed. As a result, we know surprisingly little about the safety of most medications used during pregnancy or breastfeeding. After they begin being sold, case reports, registries and other types of evidence are pieced together to try to provide meaningful information about specific drugs.

Unfortunately, the best information available for many prescription, over-the-counter products or supplements is “seems to be safe,” “appears to have specific harms,” or “is of uncertain safety.” Various websites, practice statements, hotlines, databases and books and articles collect this information and serve as resources for women and their care providers. The resources section on this page points you to some of these.

Some drugs have “teratogenic” effects that disrupt the healthy development of the embryo early in pregnancy. Thus, it is important to address your medicines before attempting to become pregnant. If you are currently using prescription or over-the-counter medications, discuss these with your preconception care provider. In addition to avoiding harm to the fetus and baby, it is important to have effective ways to control your health conditions. You can weigh what is known about the drug, its benefits to you, and possible other drug or drug-free options.

It is difficult to be certain that a given product will not lead to harm. In this situation, you may wish to avoid any exposure that could be harmful due to our limited knowledge about its effects.

Even cold or headache remedies sold without a prescription (over-the-counter) at a pharmacy or drug store are strong medicine. Tell your health care provider what you are taking in case it can affect your ability to get pregnant or in case it can affect a growing fetus.

Most “natural” remedies and herbal dietary supplements have not been tested to determine their effects during pregnancy. Many have active ingredients with strong biological effects, and their safety is not certain. Also, some of these products interact dangerously with certain prescription medicines. Moreover, the actual content of a specific herb or other supplement often varies greatly both within a brand and across brands. You should talk to your health care provider before you become pregnant about any alternative remedies you use to make sure you don’t put yourself or your future baby at risk. Check out the Related Resources section for more information.

Alcohol

• American College of Obstetricians & Gynecologists’ (ACOG) Frequently Asked Questions: Alcohol and Women fact sheet
• CDC’s Fetal Alcohol Spectrum Disorders page

• American College of Obstetricians & Gynecologists’ (ACOG) Frequently Asked Questions: It’s Time to Quit Smoking fact sheet
• National Institute on Drug Abuse’s DrugFacts: Electronic Cigarettes (e-Cigarettes) page
• Smokefree.gov
• For help quitting, call 1-800-QUIT-NOW (1-800-784-8669)
• American College of Nurse-Midwives’ Smoking and Women’s Health: Tips on Why and How to Quit

• March of Dimes’ Street Drugs and Pregnancy page
• National Institute on Drug Abuse’s Prenatal Effects page
• National Institute on Drug Abuse’s Substance Use While Pregnant and Breastfeeding page

• Find help: Behavioral Health Treatment Services Locator

• MothertoBaby (from the Organization of Teratology Information Specialists)
• National Institutes of Health Dietary Supplement fact sheets
• Womenshealth.gov Pregnancy and Medicines Fact Sheet
• U.S. Food and Drug Administration’s List of Pregnancy Exposure Registries