Inverse power-law distributions and 1/F power spectra in fetal breathing dynamics

It is shown that fetal breathing dynamics demonstrate an inverse power-law relationship in the distributions of the inter-burst intervals and in the power spectrum. Furthermore, it is shown how these fractal characteristics change as a function of gestational age of the fetus. The observation of the inverse power-law relationship in the fetal breathing dynamics supports the proposal that fractal mechanisms may be involved in the regulation of breathing rate variability, giving rise to self-similar fluctuations over multiple time scales