International Board of Certified Lactation Consultant (IBCLC) Practice Exam

Which component of breast milk is considered the least variable?

1. Immunoglobulin A

2. Lactose

3. Lactoferrin

4. Fat

The correct answer is: Lactose

Lactose is considered the least variable component of breast milk. This is important to understand because lactose is the primary carbohydrate in breast milk, and it usually constitutes about 7% of the total composition, with minimal fluctuation between different mothers and stages of lactation. This consistency ensures that all breastfeeding infants receive a reliable source of energy and contributes to the development of a healthy gut microbiota. In contrast, other components of breast milk, such as immunoglobulin A and lactoferrin, can show significant variation depending on factors like maternal health, diet, and the infant's needs. These components are crucial for immune protection and development but reflect a more individualized response, which leads to their variability. Similarly, the fat content can vary considerably based on factors such as the time of day, the stage of lactation, and maternal diet. Understanding these differences can aid lactation consultants in providing appropriate guidance to breastfeeding mothers.