top of page

Why Conventional Reference Ranges Don't Stack up in Pregnancy

Updated: Jan 4


Reference ranges on a pathology report from a laboratory are determined by men or non-pregnant women. If you've followed or worked with me for long enough you'll also know that standard reference ranges are not reflective of optimal health or function, they typically represent the general population minus the bottom and top five percent. Therefore, it logically makes no sense to compare a pregnant female striving for optimal health against a standard lab reference range. It's not just logic or my opinion however, there is research to conclude that most analytes change during pregnancy thus it's important to use specific reference ranges during pregnancy.


The Physiology

It doesn't take a degree in health sciences to appreciate that many physiological changes are taking place during pregnancy. Most of these changes take place very soon after conception and continue well into late gestation. It's the adaptations taking place to accomodate the needs of mother and baby that also result in many signifiant changes in pathology values. This article won't outline all implicated pathology but I do want to highlight some key values to be aware of including liver function panel, CRP, iron studies, full blood examination, electrolytes, thyroid and lipids.