Altered Fractal and Irregular Heart Rate Behavior in Sick Fetuses

The purpose of this study was to show that abnormal fractal correlation and irregularity of heart rate behavior were altered in intrauterine growth restricted fetuses (IUGR group) and fetuses whose mothers had maternal pregnancy induced hypertension (PIH group). We analyzed fetal heart rate data of 5000 points in normal (n=98), IUGR (n=45), and PIH (n=46) fetuses, with their gestational ages > 38 weeks and without any perinatal complication. We calculate approximate entropy for the quantifying irregularity, and short-range (< or equal to 80 beats, alpha 1) and long-range (>80 beats, alpha 2) fractal scaling exponent for quantifying the fractal correlation properties. We also performed spectral analysis. In the IUGR group, statistical, the spectral measures, alpha 2, and alpha 2/alpha 1 were significantly higher and the approximate entropy was significantly lower than in the normal group. In the PIH group, alpha 1 was significantly lower and alpha 2 and alpha 2/alpha 1 were significantly higher. The fetuses associated with either IUGR or PIH, although they are not severely compromised, showed abnormal fractal and/or irregular heart rate behavior.
Pres. at Fractal 2000, "Complexity and Fractals in the Sciences", 6th International Multidisciplinary Conference, 16-19 Apr 2000, Singapore. --Original contains color plates: All DTIC reproductions will be in black and white. This article is from ADA392358 Paradigms of Complexity. Fractals and Structures in the Sciences