Serum biomarkers and Doppler pulsatile index increases likelihood ratio for prediction of preeclampsia in the second trimester of pregnancy

This study aims to compare the accuracy of risk prediction for preeclampsia (PE) of three calculators during the second trimester of gestation: American College of Obstetricians and Gynaecologists (ACOG), National Institute for Health and Care Excellence (NICE), and Foetal Medicine Foundation (FMF). Complete medical history, mean uterine artery Doppler pulsatile index were performed (PI) and venous blood samples for placental growth factor (PIGF), soluble fms-like tyrosine kinase-1 (sFLT-1), and Endoglin measurements were obtained from 214 women between 20-24 weeks gestation. PE frequency was 8.4% (18/214). Sensitivity and specificity were 94.4% and 37.2% and 44.4% and 74.5% for ACOG and NICE respectively. Sensitivity for FMF was 66.7% and 44.4% at <32 weeks and <36 weeks respectively and specificity was 97.2% and 98.1%. The highest positive likelihood ratio, 22, was obtained for FMF as compared to 1.49 and 1.76 for ACOG and NICE. These findings suggest that the addition of US and serum biomarkers in the FMF calculator increases accuracy for prediction of PE.Impact Statement What is already known on this subject? Several strategies have been implemented to evaluate risk for PE. The ACOG and NICE calculators, based on medical and anthropomorphic data, and the FMF calculator, which includes ultrasound and serum biomarkers, have been used for the prediction of PE risk in the first trimester of gestation. What do the results of this study add? Although the identification of markers for the prediction of PE during the first trimester of pregnancy has been of major clinical interest, in many countries women attend their first prenatal visit up until the second trimester of pregnancy. This is the first multicentre study in Latin American population to compare the three risk prediction systems including serum biomarkers during the second trimester of pregnancy. What are the implications of these findings for clinical practice and/or further research? We propose the FMF calculator (including PI and serum biomarkers) as a useful tool for PE risk detection during the second trimester of pregnancy. However, as this study is limited by its small sample size, larger multicenter studies are needed to confirm our findings and assert the usefulness of the FMF calculator.