Drugs During Pregnancy

Sometimes the medicine you take during pregnancy can enter the fetus and cause damage or even birth defects. This can be true for prescription drugs, over-the-counter medicines or herbal supplements. Some drugs are known to cause birth defects and damage to the fetus, while other pose a lesser risk it always best to check with your health care provider before taking any medications.


The risk of damage being done to the fetus is the greatest in the first weeks of pregnancy. This is when the major organs are being developed. Even if a drug is not considered a risk in early stages of pregnancy, there may still be negative effects for the baby later. To be sure it is best to avoid all medicines if possible.

Some drugs are not safe to take during pregnancy, even if they were prescribed for you before you became pregnant. Always be sure your health care provider knows you are pregnant. Keep in mind that other things like herbal teas, caffeine, vitamins, tobacco, and alcohol can affect the growing fetus.

Drugs taken during pregnancy reach the fetus primarily by crossing the placenta. This same route is taken by oxygen and nutrients going to the fetus. The drugs that a pregnant woman takes can affect the fetus in several ways.

*Directly, causing damage, abnormal development leading to birth defects or death.

*Altering the function of the placenta, usually by causing blood vessels to narrow (constrict) and reduce the supply of oxygen and nutrients. This can cause an underweight and underdeveloped baby.

*Forceful contractions of the muscles of the uterus. This can cause indirect injury to the fetus by reducing blood supply or triggering pre-term labor and delivery.

These drugs have been linked to birth defects.

Accutane (an anti-acne drug)

Lithium (an anti-depressant)

Tegison (used to treat psoriasis)

Coumadin (an anti-coagulant)

Chloramphenicol, Nitrofurantoin and Tetracycline (antibiotics)

The FDA has a system to rate drugs in terms of their safety, but many drugs have not been studied in pregnant women to see if they cause damage to the growing fetus. Of course, the safest system is to avoid all drugs but when necessary contact your doctor.

Category A - drugs that have been tested for safety and have been found to be safe.
Category B - drugs that have been frequently used and do not appear to cause major birth defects or other problems.
Category C - drugs that are more likely to cause problems for the mother or the fetus. Many of these drugs do not have safety studies in progress or studies are not finished. These drugs often come with a warning that they should only be used when the benefits outweigh the risks.
Category D – drugs that have clear health risks for the fetus.
Category X – drugs that have been shown to cause birth defects and should never be taken during pregnancy.

For more information on which drugs pose risks and dangers for pregnant women check the link below.

http://www.merck.com/mmhe/sec22/ch259/ch259a.html


By Renee Rotto