Reference intervals and longitudinal changes in copeptin and MR-proADM concentrations during pregnancy

Area of Science:

• Biomarker research
• Reproductive medicine
• Clinical chemistry

Background:

• Vasopressin and adrenomedullin by-products, copeptin and MR-proADM, show promise for preeclampsia detection.
• Clinical application is limited by a lack of trimester-specific reference intervals.
• This study aimed to establish these intervals in healthy pregnant women.

Purpose of the Study:

• To determine trimester-specific reference intervals for copeptin and MR-proADM in disease-free pregnant women.
• To provide data for improved clinical interpretation of these biomarkers in preeclampsia screening.

Main Methods:

• Recruitment of low-risk pregnant women with strict exclusion criteria.
• Blood sample collection at multiple gestational points (9-13, 27-29, 36-39 weeks) and postpartum.
• Analysis of copeptin and MR-proADM using the Kryptor compact plus assay.

Main Results:

• Copeptin levels increased during pregnancy, with 97.5th percentiles below the non-pregnant upper reference limit.
• MR-proADM concentrations also increased significantly, exceeding three times the non-pregnant upper reference limit in trimesters 2 and 3.
• Substantial increases highlight the need for pregnancy-specific thresholds.

Conclusions:

• Trimester- and assay-specific reference intervals for copeptin and MR-proADM are essential for clinical use.
• Consecutive measurements and timing are important considerations due to potentially small differences preceding preeclampsia.
• These findings support the development of more accurate preeclampsia diagnostic tools.