Developmental characteristics of inhomogeneous local irregularities in fetal heart rates
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
Developmental characteristics of fetal heart rate (FHR) dynamics were not extensively studied. We noticed that local irregularity behavior during a short-term period is quite inhomogeneous in mature fetuses. We studied the developmental property of the inhomogeneous local irregularity of FHR. FHR data of 450 normal fetuses aged between 23 and 40 weeks of gestation were studied. Multifractal analysis of FHR using structure function of FHR and calculated generalized very-short-term (<16 heartbeats) Holder exponent. All negative order Holder exponents showed statistically significant negative correlations with gestational weeks. All positive order Holder exponents showed significant positive correlations with gestatinal weeks. The result indicates that developmental change of the local irregularity occurs inhomogenously throughout the FHR. As fetus matures, when FHR changes small during the very-short-term period, the change becomes more irregular, and when FHR changes great during the period, the change becomes less irregular.