TABLE 4.

Systematic review questions, conclusion statements, and grades of the evidence supporting the conclusion statements within the context of these systematic reviews

Systematic review question: what is the relationship between never versus ever feeding human milk and childhood leukemia?

Limited evidence suggests that never versus ever being fed human milk is associated with a slightly higher risk of childhood leukemia. The evidence comparing never being fed human milk with being fed human milk for short durations (i.e., <6 mo) and risk of childhood leukemia is mixed. However, the evidence comparing never being fed human milk with being fed human milk for long durations (i.e., ≥6 mo) is mostly consistent and is associated with a slightly higher risk of childhood leukemia. (grade: limited)

Systematic review question: what is the relationship between shorter versus longer durations of any human milk feeding and childhood leukemia?

Limited but consistent evidence suggests that, among infants fed some amount of human milk, a shorter versus longer duration of any human milk feeding is associated with a slightly higher risk of childhood leukemia. (grade: limited)

Systematic review question: what is the relationship between shorter versus longer durations of exclusive human milk feeding and childhood leukemia?

There is no evidence to determine whether or not there is a relationship between shorter versus longer durations of exclusive human milk feeding and childhood leukemia. (grade: grade not assignable)

Systematic review question: What is the relationship between feeding a lower versus higher intensity, proportion, or amount of human milk to mixed-fed infants and childhood leukemia?

There is no evidence to determine whether or not there is a relationship between feeding a lower versus higher intensity, proportion, or amount of human milk to mixed-fed infants and childhood leukemia. (grade: grade not assignable)