Pregnancy-specific reference intervals: should we exclude women based on body mass index?

Subjects used to calculate pregnancy-specific reference intervals must exclude those who are overweight or obese

“…There is much confusion in the letter from Dockree et al commenting on the reference intervals during normal pregnancy paper. 1,2 The values used in determining reference intervals are always selected from disease-free subjects. Adding people to these calculations with known characteristics that make a disease diagnosis likely is unwise and serves no legitimate clinical purpose.…”

Exclusion criteria for reference studies: Context is key

“…We read with interest the response 1 to our letter 2 on pregnancy-specific reference intervals and the significance of body mass index (BMI). We welcome the opportunity to address some of the key points.…”