Screening models combining maternal characteristics and multiple markers for the early prediction of preeclampsia in pregnancy: a nested case-control study

To identify maternal laboratory markers to predict the risk of preeclampsia (PE) in different stages of pregnancy, we analysed 67, 25, and 73, pregnancies developing PE at 11-13, 16-20, and 24-28 wks, respectively. Routine laboratory markers were measured in whole blood or serum and binary logistic regression analysis was used to identify predictive models. At 11-13 wks of gestation, patients who went on to develop PE showed significantly higher concentrations of alanine aminotransferase, aspartate aminotransferase, alpha-L-fucosidase, 5 '-nucleotidase, glutamyl transpeptidase, cholinesterase, and uric acid; plateletcrit was also higher. At 16-20 wks, inhibin A concentration and plateletcrit were significantly elevated. At 24-28 wks, platelets, plateletcrit, and glucose concentration were significantly elevated. Logistic regression analysis showed that an elevation in 5 '-nucleotidase was independently associated with PE at 11-13 wks. The combination of inhibin A, diastolic blood pressure, and body mass index was a significant predictor for PE at 16-20 wks, while the combination of glucose and systolic blood pressure was a significant predictor for PE at 24-28 wks. In conclusion, when combined with maternal characteristics, the measurement of 5 '-nucleotidase, inhibin A, and glucose levels, represents a potentially valuable risk assessment for PE.Impact statement What is already known on this subject? Preeclampsia (PE) may be viewed as a spectrum of disorders with a severity that is reflected in the levels of specific biomarkers. Consequently, there is a clear need for additional biomarkers that can be used to stratify pregnancies as high or low risk soon after conception. What do the results of this study add? At 11-13 wks of gestation, maternal assays for platelets, plateletcrit, alanine aminotransferase, aspartate aminotransferase, alpha-L-fucosidase, 5 '-nucleotidase, glutamyl transpeptidase, cholinesterase, and uric acid, demonstrated significantly higher values in patients with PE when compared with normal controls. Furthermore, assay results for inhibin A and platelets showed increased values at 16-20 wks of gestation. Assays performed at 24-28 wks of gestation revealed elevated levels of platelets, plateletcrit, and glucose. Our analysis indicated that increases in the levels of 5 '-nucleotidase, inhibin A, and glucose, are effective and significant biomarkers that could be used in combination with maternal characteristics to screen for PE at 11-13, 16-20, and 24-28 wks of gestation, respectively. These findings provide a new basis for our understanding of the aetiology underlying PE. What are the implications of these findings for clinical practice and/or further research? Further studies that consider the entire population are now needed and should include the investigation of laboratory markers across different stages of pregnancy. Long-term follow up would also be necessary if we are to explore the full role of laboratory markers in the pathophysiology of PE.