Understanding Drug Categories for Pregnant Women

by Pattie Hughes | More from this Blogger

If you are pregnant in the United States, you may have seen the Food and Drug Administration's use in pregnancy ratings for drugs. This rating scale has five categories. Each category is designated by a letter: A, B, C, D and X.

Category A: Drugs in the A category have been studied and the studies have not shown a risk of abnormalities in the fetus when the mother has taken the drug. The results hold true for all three trimesters of pregnancy. The studies done on these drugs are considered to be well controlled scientific studies and several have been conducted on the drug and the results have held true through each study. This is the safest category of drug. An example of a category A drug would be the thyroid medication, Levothyroxine.

Category B: Drugs in this category have been tested in animals with no adverse affect on the babies. The drug tests have been done with animals only. No human testing has been performed on pregnant women for drugs in this category. This category can also mean that animal tests showed adverse effects on the animal fetus. Studies done in pregnant women show no risk to the baby. Drugs in this category include amoxicillin and some types of insulin.

Category C: Drugs in this category have been tested on animals only. In some cases, the drug hasn't been tested in animals either in terms of effect on the fetus. No studies have been done on the effect of these drugs on pregnant women and their babies. Ventolin for asthma and antidepressants such as Zoloft fall in this category.

Category D: These drugs have been tested and the studies have shown the drug may have adverse effects on a human fetus. Sometimes the drug is necessary for the life and health of the mother. In some cases, the doctor may decide the risk is minimal and the benefit of the drug for the mother is clear. Paxil, lithium and some chemotherapy drugs fall in this category.

Category X: These drugs are known to have a high risk of fetal abnormalities when the drug is used in pregnancy. Drugs in this category are not considered safe for pregnant women and their developing babies. Accutane, which is prescribed for severe acne, falls in this category.

Related Articles:

Hypothyroidism and Trying to Conceive

The Effects of Illegal Drugs on the Fetus

Let's Talk About Herbs to Avoid During Pregnancy

Learn more about Pattie Hughes

Pattie Hughes is a freelance writer and mother of four young children. She and her husband have been married since 1992. Pattie holds a degree in Elementary Education from Florida Atlantic University.

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