Application of a Multiplex Platform to Identify Novel Biomarkers for Pregnancy Location and Viability

Determining early pregnancy location and viability can be cumbersome, often requiring serial evaluations. This study aimed to identify novel biomarker candidates for pregnancy location and viability using a pseudodiscovery high-throughput technique. This was a case-control study among patients presenting for early pregnancy assessment, including ectopic pregnancies, early pregnancy losses, and viable intrauterine pregnancies. For pregnancy location, ectopic pregnancy was considered "case" and non-ectopic considered "control." For pregnancy viability, viable intrauterine pregnancy was considered "case" and early pregnancy loss + ectopic pregnancy were considered "control." Using Proximity Extension Assay technology from Olink Proteomics, serum levels of 1012 proteins were compared separately for pregnancy location and viability. Receiver operator characteristic curves were generated to determine a biomarker's discriminative abilities. Analysis included 13 ectopic pregnancies, 76 early pregnancy losses, and 27 viable intrauterine pregnancies. For pregnancy location, 18 markers had an area under the curve (AUC) ≥0.80, with three being expressed more in ectopic compared to non-ectopic pregnancies: thyrotropin subunit beta, carbonic anhydrase 3, and DEAD (Asp-Glu-Ala-Asp) box polypeptide 58. For pregnancy viability, two markers had an AUC ≥0.80: lutropin subunit beta and serpin B8. While some of the markers had previously been implicated in early pregnancy physiology, others were from pathways not previously explored. Using a high-throughput platform, a large number of proteins were screened as potential biomarkers for pregnancy location and viability, and twenty candidate biomarkers were identified. Further exploration of these proteins may facilitate validation as diagnostic tools for establishing early pregnancy diagnoses.