Women who are pregnant or thinking about becoming pregnant should consult with a physician before using any medications, supplements or recreational drugs. Although many prescription and over-the-counter drugs can be used safely during pregnancy, others can have harmful effects on the developing fetus or the natural course of the pregnancy.

Herbal remedies, supplements and recreational drugs – including legal (such as alcohol and nicotine) and illegal (such as marijuana and cocaine) substances – can also have negative impacts when used during pregnancy.

No medicines have been proven absolutely safe for use during pregnancy, according to the U.S. Department of Health and Human Services. However, many drugs are thought to be safe, and some may be beneficial during pregnancy. In addition, some medications and supplements should not be taken while breastfeeding as they can be transferred through breast milk to the baby. Women should consult with their physician when deciding which drugs are and are not safe to take during pregnancy and breastfeeding.

The use of any type of drugs, whether prescription or recreational, can have profound effects on the health of a developing fetus or the natural course of a pregnancy. In some cases, drug use may cause birth defects or other damage. Maternal drug use is thought to be responsible for at least 10 percent of birth defects, according to the American Academy of Family Physicians (AAFP). For this reason, women who are pregnant or thinking about becoming pregnant should consult with a physician before taking any medications.

The most cautious approach is not to use any medications during pregnancy. However, this is not a practical solution for most women. More than 80 percent of pregnant women take over-the-counter or prescription drugs during pregnancy, according to the AAFP. Pregnant women may need to take prescription drugs to treat conditions such as asthma, epilepsy, high cholesterol or depression. In addition, women may take over-the-counter medications to treat less severe conditions such as allergy flare-ups or minor pain. Furthermore, some drugs may be necessary during a pregnancy to treat pregnancy complications, such as gestational diabetes, preterm labor or preeclampsia.

No medicines have been proven absolutely safe for use during pregnancy, according to the U.S. Department of Health and Human Services. However, many over-the-counter and prescription drugs are thought to be safe for pregnant women. Nonetheless, others are not, including some medications that a woman may have taken safely before she became pregnant

Finally, many illegal drugs (such as marijuana and cocaine) and legal drugs, herbs and supplements (such as nicotine, alcohol, caffeine, vitamins, herbal teas and remedies) can have adverse effects when taken during pregnancy.

The risk of drug damage to a fetus is highest during the first several weeks of pregnancy, when major organs are developing. However, experts are unsure whether medications during pregnancy cause negative effects that manifest in the child later in life. In addition, the use of some drugs can negatively impact the pregnancy, such as increasing the risk of premature labor or certain types of complications, such as separation of the placenta or other bleeding problems.

For these reasons, female patients should tell all healthcare providers if they are pregnant or thinking about becoming pregnant. This can help alert physicians to avoid prescribing certain drugs, or to suggest alternatives that may be safer to use during pregnancy. Women with certain medical conditions (e.g., heart disease) might need to change their medications prior to attempting to conceive. In addition, they may need to modify or add dietary supplements. Women can also carefully check the labels of over-the-counter drugs before they purchase them. Federal law requires that all drugs known to increase risks for pregnant women must state this clearly on the packaging.

Women should remember that in many cases, the benefit of taking certain drugs far outweighs any potential risks for the mother and the fetus. In other cases, some drugs or supplements – such as folic acid (which helps prevent fetal brain and spinal cord disorders), calcium and iron – may be beneficial just before and during pregnancy.

The Food and Drug Administration (FDA) has established a system for ranking drugs according to their probable safety when used during pregnancy. These drugs are listed in five categories:

• Category A. Drugs tested for safety during pregnancy and considered to be safe. They include:
  
  
• • Folic acid
  • Vitamin B6
  • Thyroid medication (taken in moderation)
    
    
• Category B. Drugs used often during pregnancy that do not appear to cause major birth defects or other problems. These include:
  
  
• • Some antibiotics
  • Aspartame (an artificial sweetener)
  • Famotidine (used to treat stomach conditions)
  • Prednisone (cortisone)
  • Insulin (a diabetes medication)
    
    
• Category C. Drugs that are more likely to cause problems for the mother or the fetus, although safety studies have not been completed for many of these medications. These are drugs that should be used only when health benefits outweigh risks, and include:
  
  
• • Some antidepressants (used to treat anxiety disorders and depression)
  • Several drugs used to treat vaginal yeast infections
  • Pseudoephedrine (a cold medication)
  • Ciprofloxacin (an antibiotic)
    
    
• Category D. Drugs that have clear health risks for the fetus. These include:
  
  
• • Alcohol
  • Nicotine
  • Lithium (used to treat bipolar disorder)
  • Phenytoin (an anticonvulsant)
  • Most chemotherapy drugs
    
    
• Category X. Drugs that have been shown to cause birth defects and that should never be taken during pregnancy. A prescribing physician might insist that a patient use a reliable form of contraception while taking these medications known to cause severe birth defects. These drugs include:
  
  
• • Thalidomide (used to treat leprosy and being studied to treat other diseases)
    
    
  • Certain drugs used to treat skin conditions such as cystic acne and psoriasis
    
    
  • Diethylstilbestrol (DES, a synthetic estrogen previously used to prevent miscarriage)

Other drugs that have been classified using FDA guidelines to determine their safety during pregnancy include:

Over-the-counter pain medications

Over-the-counter decongestants,
expectorants and antihistamines

Over-the-counter antidiarrheal medications

Over-the-counter antacid preparations

Over-the-counter vaginal antifungal medications

Aspirin – one of the most commonly used drugs in the world – and other drugs containing salicylate should not be used during pregnancy, particularly during the third trimester. The World Health Organization (WHO) has also stated that nursing mothers should not use aspirin, as it may be transferred through breast milk to the baby. Aspirin is associated with Reye syndrome, a rare condition that affects the brain and liver in children who receive aspirin during a viral illness. Other conditions associated with the use of salicylates during pregnancy include:

• Perinatal mortality
• Neonatal hemorrhage
• Decreased birth weight
• Prolonged gestation and labor
• Possible birth defects
  

However, some high-risk pregnancy conditions call for the use of low dose aspirin (baby aspirin) during a pregnancy, and this can be used safely under close medical supervision. Also, acetylsalicylate – a common ingredient in many over-the-counter painkillers – may cause pregnancy to last longer, and may increase the risk of severe bleeding prior to and after delivery.

In addition to medicines, other types of drugs and supplements may pose dangers to women during pregnancy. These include:

• Herbal remedies and supplements. The safety of herbal remedies and supplements during pregnancy is largely unknown, as they are not required by the FDA to undergo rigorous testing. However, these products may contain agents that can harm the fetus or cause difficulties during the pregnancy. Thus, herbal products should not be taken unless a physician approves their use.
  
  
• Recreational drugs. Legal and illegal recreational drugs may pose danger to a pregnant woman. These include:
  
  
• • Nicotine and other chemicals in tobacco products. Smoking is associated with higher incidences of miscarriage, stillbirth, bleeding, premature birth and low birth weight. It has also been linked to sudden infant death syndrome (SIDS), a disorder in which infants suddenly die for no apparent reason. Smoking while pregnant can also have long-term ramifications for the physical growth and intellectual development of children.
    
    
  • Alcohol. A pregnant woman who drinks alcohol may trigger fetal alcohol syndrome (FAS), which causes problems in the fetus such as mental slowness, poor growth rates, facial defects and head size that is smaller than normal. Women should not drink before or during pregnancy, or while nursing.
    
    
  • Illegal drugs. Marijuana, cocaine and other illegal drugs raise the risk of miscarriage, premature birth and birth defects. Use of some drugs can cause the child to be born with a physical addiction to the substance that may result in withdrawal symptoms after birth.

Pregnant women generally should limit themselves to one or two cups daily of drinks that contain caffeine. Caffeine easily passes through the placenta to the fetus, and levels of caffeine stay elevated longer in the fetus than in the mother. It can also pass through breast milk and cause agitation in nursing babies.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Women may wish to ask their doctor or healthcare professional the following questions related to drugs and pregnancy:

1. Which over-the-counter (OTC) drugs are safe to use during pregnancy?
2. Which OTC drugs should I avoid completely?
3. Can I take my usual vitamins and supplements during pregnancy?
4. What are my alternatives if I cannot take my prescribed drugs during pregnancy?
5. Can I have alcohol on a limited basis during pregnancy?
6. How will I know if a drug is safe to use during pregnancy?
7. Should I stop using certain medications if I’m trying to conceive?
8. What steps will be taken if I take a drug that is considered unsafe?
9. Are there any herbal supplements that you consider safe to use during pregnancy?
10. If I need help with eliminating the use of alcohol or drugs, can you refer me to a program?