[Drugs during pregnancy and breastfeeding: new risk categories--antibiotics as a model]

In selecting drugs for treatment during pregnancy and breastfeeding it is essential to be certain of their safety. But categories are lacking that systematically relate the current state of knowledge of individual substances--rather than just drug classes--to each trimester of pregnancy. As such a stratification of risk would be helpful, it was the aim of this study to propose a new and more differentiated classification.

Internationally available literature and electronic data bases providing details on adverse effects of individual drugs during pregnancy and breastfeeding as well as summaries of product characteristics of the drugs served as comprehensive sources of information. Account was taken of compound-specific data on toxicity during the reproductive and developmental stages, genotoxicity and carcinogenicity (in animals and in-vitro experiments) and drug-specific experience as documented in women during pregnancy and breastfeeding.

A new risk classification and appropriate recommendations for clinical management were developed to ensure the safety of drugs given during pregnancy and breastfeeding, taking into account the varying risks during the three trimesters of pregnancy and the perinatal period. Antibiotics were selected as a model for drugs in general and classified according to the new system.

The proposed new classification of risk makes it possible to select safe agents in the treatment of pregnant and/or breastfeeding women. It is based on the current state of knowledge about a particular substance, also in relationship to the developmental phase of the breastfed child.