WASHINGTON — Doctors may soon get a new way to tell which medications are safe for women to use during pregnancy and when they breastfeed.

Today, prescription drugs carry a code in the fine print of their labels that rank their pregnancy safety: Category A means it's deemed safe; Category X means it's known to harm human fetuses. A drug given the remaining B, C or D codes have varying levels of evidence one way or the other.

That's too confusing, the Food and Drug Administration declared yesterday.

So the agency proposed a change: Strip away the codes.

Replace them with clearly marked sections in the drug's label that describe what research shows about fetal risk — and whether that information comes from studies in people or only in animals — and other information, such as whether pregnant women need different doses than other patients.

If the new rule takes effect — it's open for 90 days of public comment before FDA makes a final decision — the hope is that labels eventually would lay out the pros and cons that are known in ways that help women and their doctors make more rationale decisions, said FDA's Dr. Sandra Kweder, who led the 11-year effort for a change.