What is a contraindication to breastfeeding?

Breastfeeding may pose risks in the context of cancer treatment, particularly when chemotherapeutic agents are involved. These medications can be present in breast milk and potentially harm the nursing infant. Chemotherapy drugs are specifically designed to target rapidly dividing cells, a characteristic of cancer, but they can also affect the rapidly dividing cells of an infant's developing body, leading to serious health concerns.

In contrast, while prescribed medications may have certain cautions related to breastfeeding, many can be compatible and safe based on the specific medication and timing; thus, not all prescribed medications serve as absolute contraindications. The use of illicit drugs also represents a significant risk during breastfeeding, but there are documented cases where a mother may engage in harm reduction strategies. Vitamin supplementation generally provides benefits in terms of nutrition and is not a contraindication to breastfeeding, assuming they are within recommended limits.