Differences in the Asymmetry of Beat-to-Beat Fetal Heart Rate Accelerations and Decelerations at Preterm and Term Active Labor.

Carolina López-Justo,Claudia Ivette Ledesma-Ramírez,Jorge Rodríguez-Arce,Juan Carlos Echeverría,José Javier Reyes-Lagos,Adriana Cristina Pliego-Carrillo,Miguel Ángel Peña-Castillo,Hugo Mendieta-Zerón

doi:10.3390/s21248249

Abstract

The fetal autonomic nervous system responds to uterine contractions during active labor as identified by changes in the accelerations and decelerations of fetal heart rate (FHR). Thus, this exploratory study aimed to characterize the asymmetry differences of beat-to-beat FHR accelerations and decelerations in preterm and term fetuses during active labor. In an observational study, we analyzed 10 min of fetal R-R series collected from women during active preterm labor (32–36 weeks of pregnancy, n = 17) and active term labor (38–40 weeks of pregnancy, n = 27). These data were used to calculate the Deceleration Reserve (DR), which is a novel parameter that quantifies the asymmetry of the average acceleration and deceleration capacity of the heart. In addition, relevant multiscale asymmetric indices of FHR were also computed. Lower values of DR, calculated with the input parameters of T = 50 and s = 10, were associated with labor occurring at the preterm condition (p = 0.0131). Multiscale asymmetry indices also confirmed significant (p < 0.05) differences in the asymmetry of FHR. Fetuses during moderate premature labor may experience more decaying R-R trends and a lower magnitude of decelerations compared to term fetuses. These differences of FHR dynamics might be related to the immaturity of the fetal cardiac autonomic nervous system as identified by this system response to the intense uterine activity at active labor.

Highlights

Our results indicate that obtained from the algorithm is better metry of beat-to-beat fetal heart rate (FHR) by applying Deceleration Reserve (DR) in a wide range of T and s values in comparison than acceleration capacity (AAC), average deceleration capacity (ADC), and multiscale asymmetry indices to identify differences of FHR between with the calculation of other multiscale asymmetry indices for fetuses during active term labor preterm and term conditions
Our results indicate that DR obtained from the phase rectified signal averaging (PRSA) algorithm is betto discriminate between preterm and term fetuses using DR were T = 40, s [1,2,3,4]; T = 45, ter than AAC, ADC, and multiscale asymmetry indices to identify differences of FHR bes [1,2,3,4,5,6,7,8,9,10]; T = 50, s [1,2,3,4,5,6,7,8,9,10]
These asymmetric differences of fetal heart rate dynamics might be related to the immaturity of the fetal cardiac autonomic nervous system as identified by this system response to the intense uterine activity at active labor

Summary

Introduction

The fetal heart rate (FHR) shows specific patterns during labor owing to the rhythmic contractions in the woman’s uterus. The regular contractions generate repetitive decelerations and subsequent accelerations of the FHR [1,2,3]. These patterns are associated with the response of the fetal parasympathetic and sympathetic autonomic nervous system (ANS). Continuous and accurate fetal monitoring could be considered to guarantee mother and child’s health during labor. In the current clinical practice, there is a high degree of subjectivity or a lack of medical dexterity to identify FHR accelerations and decelerations by visual evaluation [2,7,8]

Methods

Results

Discussion

Conclusion