Pattern-Segmented Heart Rate Variability Analysis During Fetal Maturation

Background: Established fetal maturation diagnostics evaluates heart rate patterns (HRP) such as baseline, variability, decelerations (DC) and accelerations (AC). Fetal heart rate variability (fHRV) parameters provide valuable additional information. Their dependence on those patterns is crucial but not sufficiently explored. Objective of the present work is the comparison of the maturational age prediction using fHRV parameters with respect to those patterns. Methods: We analyzed 555 recordings, each one lasting 30 minutes, of normal fetuses, from 19 weeks of gestation (WGA) onward. We applied a pattern-segmented fHRV analysis of linear and nonlinear parameters under consideration of the fetal behavioral states to evaluate the WGA prediction accuracy, based on linear regression models that were tested using a repeated cross validation scheme. Results/Conclusion: fHRV parameters calculated under exclusion of DCs, show a significantly improved age dependency compared to the standard method, especially in the early weeks of the second half pregnancy. This aspect may improve the early sensitive identification of maturation disorders of the fetus.