New and expectant mothers already have a lot on their minds. Now the U-S Food and Drug Administration is trying to help them take the guesswork out of which medicines they should avoid while pregnant or breastfeeding.

Doctors say there still is much to learn about how medication may affect a fetus or a newborn infant. And the information available isn’t always clearly presented on drug labels.

Under the F-D-A’s new plan, the drug categories previously used to indicate the risk to a fetus would be eliminated. Currently, category A drugs haven’t been shown to cause birth defects, while a category X drug should be avoided while pregnant or breastfeeding. Other letters are used to show various levels of risk.

In the new system, drugs would be labeled with three information summaries: the risks to the fetus, the effects of the disease on the mother and baby, and any supporting data. There would also be a lactation section, which would detail what is known about the effects on a breastfeeding infant.

According to the F-D-A, there are about six-million pregnancies a year in the United States. Each pregnant woman takes an average of three to five prescription drugs. Some might treat chronic conditions, such as asthma or depression. Others might help the side effects of pregnancy.

But clear labeling isn’t meant to replace important discussions between women and their doctors. Pregnant and breastfeeding women should consult their physician about all prescription medications they take during this very important time.