Multiparameter analysis of heart rate variability signal for the investigation of high risk fetuses

The purpose of this study is to evaluate the information content provided by the fluximetry information and the analysis of fetal heart rate (FHR) signals, obtained from cardiotocographic recordings, during prenatal monitoring, in a high risk population. The parameters assessed on FHR signals are divided in: (i) time domain parameters (ii) frequency domain parameters, and (iii) the complexity parameters: Approximate Entropy (ApEn), Sample Entropy (SampEn), Multiscale Entropy (MSE), the Lempel Ziv Complexity (LZC) and the Detrended Fluctuation Analysis (DFA). The fetuses were classified as fetal growth restricted (FGR). The results have shown that the FGR fetuses preterm delivered have produced a markedly reduced heart rate variability in respect with those fetuses which were characterized by an alteration in the fluximetric indices. The normal range in cord blood sampling analysis excludes the prolonged hypoxia as a causing factor. Finally, it seems that the residual cardiovascular response in FGR fetuses could be correlated to an alteration in the flow of the main vessels.