Comparison of fetal heart rate patterns using nonlinear dynamics in breech versus cephalic presentation at term

Fetal behavioral dynamics in cephalic versus breech presentations

“…However, our findings contrast with those of a recent study performed by Park et al (), who failed to find any difference in linear and entropy FHR analysis between breech and cephalic presentations. This could have occurred because of different inclusion criteria, namely in the obstetrical characteristics of the studied population, the conditions used for FHR recording, the occurrence of maternal fasting, and the time lag between acquisition and delivery, which averaged 1 week and was not always by cesarean section.…”

“…Moreover, although Park et al () also used external FHR recording, different equipment and different signal pre‐processing methods were employed, with a sampling and re‐sampling rates at 2.3 Hz and 2 Hz, respectively. Shorter FHR tracings were also selected, as well as 20‐min segments within each tracing (Park et al, ), which could have contained more pattern transitions (Gonçalves, Rocha, Ayres de Campos, & Bernardes, ; Gonçalves et al, ). All of these differences could have influenced the final results (Gonçalves, Costa, et al, ; Gonçalves et al, ).…”

“…Differences in fetal neurodevelopment, between cephalic and breech presentations, can have important implications on post‐neonatal perceptual and learning capabilities (Sørensen et al, ; Van der Meulen, Davies, & Kisilevsky, ). Moreover, the criteria used to define normality in fetal behavior and related variables, such as the fetal heart rate (FHR), can also be different in breech and cephalic fetuses (Kean, Suwanrath, Gargari, Sahota, & James, ; Park, Ryu, Shim, Hoh, & Park, ). Studies on fetal behavior involving ultrasonographic monitoring of different movements are complex, time consuming, and technically difficult to conduct, but linear and entropy analysis of FHR recording provides a simpler alternative, namely by evaluating the activity of the autonomic nervous system and that of the more complex physiological control systems (Gonçalves, Bernardes, Rocha, & Ayres‐de‐Campos, ).…”

Complex and irregular heart rate dynamics in fetuses compromised by maternal anemia as a high-risk pregnancy

“…In the CD calculation, we used 2400 data points, and the CD value is the slope of the correlation integral curve of m = 20 at the scaling region. The scaling region, as previously reported [15,28], is in the range of -2 < log C(r) < -1.…”

“…In the antepartum period, entropy indices [12,28,35], fractal indices [13], small-for-gestational-age fetuses [15], and typical FHR patterns [10,25,26] have been determined. Entropy indices have been proven to be a powerful tool for the study of nonlinearity in the cardiovascular control system [17,30,31,34,36].…”