Drugs and Pre-Existing Conditions
At your preconception visit, you need to talk to your health-care provider about any chronic medical conditions you have and how they might affect your pregnancy. You also need to discuss any prescription medications you take, as well as over-the-counter drugs.
Medical Conditions
High blood pressure, diabetes, autoimmune diseases (such as rheumatoid arthritis or lupus), epilepsy, obesity, and asthma are all conditions that can be affected by pregnancy. They can also impact your pregnancy and the health of your baby. The good news is that most of the time, an experienced health-care provider can carefully manage any pre-existing conditions so that you can have a healthy and uneventful pregnancy.
Hypothyroidism (an underactive thyroid) is another important condition. Recent studies have shown that women with uncorrected hypothyroidism have an increased risk of having a baby with neurodevelopmental delay. This is even true of women who have subclinical hypothyroidism. In this case, blood tests show hypothyroidism even though the woman has no symptoms. This condition is fairly common in women, especially in older women.
For this reason, the American Association of Clinical Endocrinologists recommends that women in the preconception period and in the first trimester of pregnancy be tested for hypothyroidism and that thyroid replacement medication be given when necessary. The American College of Obstetricians and Gynecologists (ACOG) has not endorsed this recommendation to date. However, in view of potential adverse effects on the baby, and the safety of thyroid replacement medication, it is probably a good idea to be tested, even if you don't have symptoms of hypothyroidism.
Drugs
If you are taking any prescription medications, you should bring a complete list to your preconception appointment. While some medications are not safe to take during pregnancy, others may be safe. You and your healthcare provider may need to balance the risks and benefits before deciding what to do. In some cases you may be able to continue on your medication until you learn you are pregnant.
According the American Academy of Family Physicians, 10 percent of birth defects result from medications taken by the mother during pregnancy. Because of this, it is wise to avoid taking anything unless your doctor specifically approves it.
Talk to your health-care provider about over-the-counter medications. Most providers recommend that you avoid most of these while pregnant or trying to conceive, although acetaminophen (brand name Tylenol) and antacids are considered safe. In particular, you want to avoid ibuprofen (brand name Advil) and aspirin.
Read the ingredients of over-the-counter medications carefully. Many contain alcohol and adrenaline-like substances. If you are not sure it is safe, ask your physician. The safety of most herbal remedies in pregnancy has not been studied and their safety is not certain. It is probably best to avoid these.

