See also:

• Baby on the Way? Keep Smoking at Bay
• The Dangers of Drinking for Two: Alcohol and Birth Defects

When a woman asks if it is safe to take a particular drug during pregnancy, there is rarely a definite yes or no answer. The key to taking medicines during pregnancy—or when you are trying to get pregnant—is weighing the benefits of the medicine against the potential risks to the fetus.

Be Proactive and Ask Questions

When possible, think ahead. It is best to address questions about medicines and vitamins before you are pregnant. Ask your doctor about the over-the-counter medicines you currently use. These include drugs for everyday conditions, such as heartburn, allergies, or headaches. In addition, check with your doctor about any prescription medicines you are taking. Both types of medicines may need to be either discontinued or changed before you get pregnant.

Women With Chronic Conditions Have Special Needs

Not long ago, many women with chronic conditions, such as lupus or diabetes, considered pregnancy to be too risky. However, because of advances in the fields of high risk obstetrics and internal medicine, many of these women now deliver healthy babies. Sandra Gangell, of the Pregnancy Risk Network of People, Inc., encourages women with chronic health problems to assemble a healthcare team to help them manage their disease processes and medicines during this important time. Ideally, the team should be formed before conception. She also states that enlisting a teratology specialist is particularly important, as these doctors specialize in understanding how medicines and other substances effect a developing fetus. Ronald J. Ruggiero, PharmD, of the University of California San Francisco, agrees with Gangell. He notes that obstetricians cannot be expected to know the effects of all medicines used for chronic conditions.

Members of the team may include:

• An obstetric care provider who specializes in high risk pregnancies
• The doctor managing the chronic condition
• The primary care provider (if not managing the chronic condition or the pregnancy)
• A teratology specialist
• A genetic counselor

The Role of Teratology Specialists

The Organization of Teratology Information Services (OTIS) provides expert information about prenatal exposures to medicines, chemicals, and other substances. OTIS member organizations do not prescribe or recommend treatments; they provide objective information about the following:

• Medicines a woman took before she realized she was pregnant
• Medicines prescribed for an illness that occurs during pregnancy
• Medicines for chronic conditions

FDA Safety Rating

The US Food and Drug Administration (FDA) currently requires that drugs be categorized according to their risk to pregnant women.

Evaluating the Risks and Benefits

In some cases, such as when women have asthma, depression, diabetes, high blood pressure, or HIV, stopping medicine may be significantly more harmful to the fetus than taking the drugs during pregnancy. In these types of cases, OTIS can provide information about a specific drug and the risk to the fetus, based on timing during the pregnancy. Some drugs are potentially harmful early in the pregnancy, but not later on. Conversely, others present a greater risk around the time of delivery. OTIS can also inform you about the risk/benefit profile of medicines that can help you manage your condition during pregnancy.

"Don't stop taking medicine for a chronic condition if a home pregnancy test is positive," warns Gangell. Check with your healthcare provider first.

According to Gangell, substances that pose a high risk during pregnancy include the following:

• Accutane
• ACE inhibitors
• Alcohol
• Aspirin (This depends on the dose and the trimester; beware of aspirin in combination with certain over-the-counter medicines.)
• Cocaine
• Lithium
• Methamphetamine
• Methotrexate
• Nicotine
• Non-steroidal anti-inflammatory (NSAIDs) medicines
• Propylthiouracil
• Streptomycin
• Tegison or Soriatane
• Tetracycline
• Thalidomide
• Warfarin

Note on Herbs and Supplements

Dr. Ruggiero warns pregnant women not to take herbal remedies or supplements, because there are no reliable studies about their effects during pregnancy. Since they are not regulated the way conventional medicines are, there is no way to gauge the purity or actual dose of the substance you are taking. There may be many alternative and complementary therapies that are safe and/or helpful in pregnancy. But you need to do your research to find out if there is information about their safety in pregnancy, and physicians recommend that you discuss this with them as well.

An excellent resource about both drugs and other supplements is the Mother Risk Program hosted by the Hospital for Sick Children in Toronto, Canada.