The U.S. Food and Drug Administration plans to update a decades-old labeling system to better-inform pregnant and lactating women about different medicines' potential effects.

The changes will include major revisions in the subsections seen on medicine labels regarding pregnancy and breastfeeding.

"FDA wants pregnant and breastfeeding women and their health care providers to benefit from the most useful and latest information about their prescription medicines," said Sandra Kweder, M.D., deputy director of FDA's Office of New Drugs.

On average, women take between three and five medications over the course of their pregnancy so these new labels will play a crucial role in the patients' awareness and decision-making. The revised labeling will include additional information about whether or not medicine can get into breast milk and the potential effects it can have on the infant.

The labeling will also now include a subsections called "Females and Males of Reproductive Potential," which will outline the medicine's effects on "pregnancy testing, birth control and a medication's effect on fertility."

"For medications that may cause infertility or present risks in pregnancy, the revised labeling will include information to be considered when deciding such issues as birth control or planning a pregnancy," Kweder said.

Until now the risk a medicine imposes on pregnant women was based on a five-letter system (A, B, C, D and X), but this was often found to be confusing to patients because it was overly simplistic and lacking in detail.

"The revised labeling will change that," Kweder said. "Now doctors will have up-to-date and well-organized information on pregnancy and lactation. They will be in a better position to help their patients make critical decisions."

The FDA noted all medication decisions made during pregnancies should be gone over with a physician, but the new labeling rules could help keep patients informed. The new labels will take several years to completely replace the old lettering system.

"The greatest benefit to patients is that these changes will result in better-informed prescribing based on the latest scientific information for thousands of medical products," Kweder adds. "Our goal is to empower health professionals and patients so that women can have confidence in treatment decisions for themselves and their families."