The role and challenges of biomarkers in spontaneous preterm birth and preeclampsia.

Biomarkers associated with spontaneous preterm birth and preeclampsia have been discovered in patients who experience these adverse obstetrical outcomes. The identification of such biomarkers holds promise in both facilitating the early identification of those patients at greatest risk and enhancing our understanding of these disease processes to determine therapeutic interventions. To that end, our objective was to review the existing literature to determine the utility of biomarkers in the risk stratification of spontaneous preterm birth and preeclampsia. We found that despite the promise of some biomarkers in identifying patients at increased risk for spontaneous preterm birth and/or preeclampsia, the use of biomarkers in clinical practice to predict adverse obstetrical outcome remains challenging. Although data from small discovery studies may be encouraging, progress with biomarker research remains limited by the lack of validation of these discovered biomarkers. Furthermore, owing to the heterogeneity of existing studies, generalizable conclusions are difficult to understand, meta-analyses are challenging to perform, and agreement on cut-point standardization is difficult. The identification of an abnormal biomarker level does not guarantee whether or when an adverse clinical event might occur. Our lack of understanding of the true etiologies of these disease processes leaves us without definitive interventions to prevent spontaneous preterm birth and preeclampsia from occurring.