The Pregnancy and Lactation Labeling Rule (PLLR) replaced the FDA's former pregnancy risk category labels (A, B, C, D, X) starting in 2015. The previous letter categories were often criticized for being overly simplistic and sometimes misleading, as they did not provide detailed information about the potential risks and benefits of medication use during pregnancy and lactation.

The PLLR system was introduced to provide a more comprehensive and informative approach. Instead of a letter category, the PLLR requires drug labels to include:
- A summary of the risks based on available human and animal data.
- Information on the drug's effects on pregnancy, lactation, and reproduction.
- Relevant clinical considerations to assist healthcare providers in making informed decisions.

This narrative format allows for a clearer understanding of the potential risks and benefits, supporting individualized patient care and safer medication use during pregnancy and breastfeeding.

Key Points:
- PLLR replaced the letter categorization system in 2015.
- Focuses on detailed, evidence-based risk summaries.
- Includes separate sections for pregnancy, lactation, and reproductive potential.
- Aims to improve clinical decision-making with more meaningful data.