Evaluation of the effectiveness of fetal heart rate analysis using phonocardiography with novel mathematical methods of audiogram processing

Aim . To evaluate the sensitivity and specificity of a phonocardiography-based method for diagnosing fetal hypoxia using the FetaCare software and hardware complex. Materials and Methods. The study included 204 pregnant women with a high degree of perinatal risk who were stratified into three groups by gestational age: 1) 26–31.6 weeks; 2) 32–36.6 weeks; 3) 37–41 weeks. Phonocardiography records of the fetus were obtained for all participants, followed by mathematical audio data processing and construction of cardiointervalograms. Fetal condition was assessed based on cardiointervalogram-derived parameters: basal fetal heart rate, oscillation amplitude, number of oscillations, acceleration amplitude, number of accelerations, long-term variation, and short-term variation. Sensitivity and specificity of the method was calculated based on short-term variation and long-term variation. Results . Depending on the gestational age group, sensitivity ranged from 40 % to 100 %, while specificity ranged from 95% to 100 %. Conclusion . Diagnostic accuracy of a phonocardiography- and audiogram processing-based heart rate analysis increased with gestational age. Before 32 weeks, it accuracy remained low, requiring the use of additional fetal examination methods to make a decision on the need for delivery. This study demonstrates that the informativeness of phonocardiography with novel audio data processing methods can be comparable to cardiotocography, which is currently widely used in clinical practice.