Fetal development, nonlinear heart rate dynamics, and self-organization

摘要

Background: The fetal precursors of mental and cardiovascular disease in later age are an important issue of developmental medicine. We investigate the question whether key parameters of fetal development reflect self-organization principles. From the systems theoretical point of view self-organization means the evolution of a previously less organized system into a higher organized form in the absence of external control. This process is characterized by a move from a large region of state space to a persistent smaller one, under the control of the system itself, and the development of correlations over time or space for previously independent locally operating variables.Aim: The object of the present work is to describe associations between the development of fetal heart rate patterns and characteristics of self-organization.Study design: From 78 normal fetuses, gestational age 23-40 weeks heart beat interval series, 30 min duration, 1 kHz sampling rate were recorded by magnetocardiography. As indices of fetal development several indices which are typically associated with self-organization were analyzed.Results: With development the variability of heart rate increased, the number of acceleration increased, and autonomic information flow increased over large time scales. These features are associated with essential self-organization characteristics, namely necessary variability, loss of degrees of freedom, and emergence of global order.Conclusion: Heart rate characteristics interpreted following the systems theoretic concept of self-organization may provide new insights into the fetal development with implications for more appropriate diagnosis and prenatal treatment.