Related information: Pregnancy and medicines fact sheet. 
You and your baby are connected. The medicines you use, including over the counter, herbal, and prescription drugs or supplements, might get into your baby's body, too. Many medicines and herbs are known to cause problems during pregnancy, including birth defects. For some medicines, we don't know that much about how they might affect pregnancy or the developing fetus. This is because medicines are rarely tested on pregnant women for fear of harming the fetus. 
Mothers-to-be might wonder if it's safe to use medicines during pregnancy. There is no clear-cut answer to this question. Your doctor can help you make the choice whether to use a medicine. Labels on prescription and over-the-counter drugs have information to help you and your doctor make this choice. In the future, a new prescription drug label will make it easier for women and their doctors to weigh the benefits and risks of using prescription medicines during pregnancy. 
Always speak with your doctor before you start or stop any medicine. Not using medicine that you need may be more harmful to you and your baby than using the medicine. 

Weighing benefits and risks 
When deciding whether to use a medicine in pregnancy, you and your doctor need to talk about the medicine's benefits and the risks. 
•    Benefits – what are the good things the medicine can do for me and my growing baby? 
•    Risks – what are the ways the medicine might harm me or my growing baby? 
There may be times during pregnancy when using medicine is a choice. For example, if you get a cold, you may decide to "live with" your stuffy nose instead of using the "stuffy nose" medicine you use when you are not pregnant. 
Other times during pregnancy, using medicine is not a choice — it is needed. For example, you might need to use medicine to control an existing health problem like asthma, diabetes, depression, or seizures. Or, you might need a medicine for a few days, such as an antibiotic to treat a bladder infection or strep throat. Also, some women have a pregnancy problem that needs medicine treatment. These problems include severe nausea and vomiting, earlier pregnancy losses, or preterm labor. 

Using herbal or dietary supplements and other "natural" products 
You might think herbs are safe because they are "natural." But, except for some vitamins, little is known about using herbal or dietary supplements while pregnant. Some herbal remedy labels claim they will help with pregnancy. But, most often there are no good studies to show if these claims are true or if the herb can cause harm to you or your baby. Also, some herbs that are safe when used in small amounts as food might be harmful when used in large amounts as medicines. So, talk with your doctor before using any herbal or dietary supplement or natural product. These products may contain things that could harm you or your growing baby.