Cell-Free Fetal DNA for the Prediction of Pre-Eclampsia at the First and Second Trimesters: A Systematic Review and Meta-Analysis.

CffDNA quantification is a marker for predicting the development of both early-onset PE and 'any PE'; however, it can probably only be used from the beginning of the second trimester, otherwise its predictive value is burdened with a DR that is too low or not significant. Due to the heterogeneity and difficulty in interpreting the published data, no conclusion regarding the statistical and clinical relevance, especially for screening 'any PE', can be made at present.