Cut-off values for Gaussian first-trimester screening for early-onset preeclampsia with maternal history, biochemical markers and uterine artery Doppler

Abstract

IntroductionSeveral algorithms for first-trimester screening for preeclampsia are available; however, the Gaussian model algorithm is more likely to match the characteristics of different populations. It is recommended to validate a screening strategy before being implemented in clinical practice; unfortunately, the validation process might not be feasible in all settings. Thus, the aim of this study was to provide cut-off values for the Gaussian model for its use in clinical practice. Material and methodsThis prospective cohort study was conducted at Vall d’Hebron University Hospital (Barcelona) from October 2015 to September 2017. A total of 2641 women with singleton pregnancies were recruited. Recorded at the first-trimester scan were demographic characteristics, maternal obstetric history, maternal history, uterine artery Doppler and arterial blood pressure. Serum concentrations of pregnancy-associated plasma protein-A and placental growth factor were assessed from the first-trimester blood test. Detection rates and cut-off values for fixed 5%, 10 %, 15 %, 20 %, 25 % and 30 % false-positive rates were calculated for all combinations of markers. ResultsNinety (3.41 %) of the 2641 women developed preeclampsia, which was early-onset in 11 (0.42 %). The cut-off values and their respective detection rates, for the screening of early-onset PE by all possible combinations of markers involved in this model, are provided. DiscussionWhen external validation of first-trimester screening for preeclampsia before its clinical implementation is not feasible, the cut-off values from the Gaussian model algorithm provided in this study could be used and median values corrected prospectively if necessary.