Duration, amplitude and shape of accelerations in relation to fetal body movements in behavioral state 2F

Abstract

The relationship between fetal movements and fetal heart rate accelerations was analyzed in 34 healthy near term fetuses. Periods of coincidence 2F (C2F) with a mean duration of 34 +/- 6 minutes per fetus were selected, with a total of 463 accelerations. Nineteen percent of single body movements and 71% of compilations of movements were accompanied by an acceleration. The minimal duration of single movements associated with accelerations was 4-5 seconds. Movements with associated accelerations differed significantly in duration from movements without accelerations. The duration of accelerations was strongly correlated with the duration of movements. The amplitude of accelerations was not clearly correlated with the duration of movements, but depended on the type of movement. The shape of accelerations appeared to be dependent on the timing of the various fetal movements. In 77%, the number of notches in the accelerations was equal to the number of pauses in the movement complications. A discrepancy between notches in accelerations and pauses in movements could be explained in the majority of cases when the timing of the various movements in relation to one another was considered, or by the presence of fetal mouth movements.

The prediction of fetal acidosis at birth by computerised analysis of intrapartum cardiotocography

“…Systems for interpretation of antenatal CTG have been used in clinical practice (Beksac et al 1990; Dawes et al 1991) for the identification of features, such as basal FHR, heart rate variability and accelerations. Although some correlation between these features and other changes in fetal physiology has been shown (Van Woerden et al 1990; Dawes et al 1992) a predictive capability for perinatal outcome could not be demonstrated. The antenatal system designed by Wickham et al (1983) has been modified and used in early labour (Pello et al 1991), but they found no clear association between the measurement of FHR variation and umbilical artery base excess on delivery.…”

Signal Ambiguity and Misinterpretation of Fetal Heart Rate: A Report of Two Cases and an Overview of Suspicious Patterns

“…In contrast, FHR usually shows decelerations in response to contraction and this is more so during the second stage of labor. Furthermore, if FHR show accelerations (usually in association with fetal movement) they tend to be irregular, of short duration, limited elevations, not lasting the entire contraction [20] and usually are sporadic never showing repeated accelerations [17,18]. • Tracings of the first stage of labor showing low baseline and early-type decelerations could be produced by MHR [18,21,22].…”

Motor and Cardiac Response during Habituation Testing: Demonstration of Exaggerated Cardiac Reactivity in a Subgroup of Normal Human Fetuses

“…In general, complex movements are associated with a greater increase in heart rate than are isolated limb movements. 17 Nevertheless, this association is far from complete because the administration of gallamine to fetal sheep abolishes movement but heart rate accelerations continue to be present. 18 -19 Although somatic-cardiac coupling may possibly explain the difference in heart rate response that we observed between slow and fast motor habituators, we would expect to see, if this were the case, some trend toward habituation of FHR as the amount of fetal movement decreased with repeated stimulation.…”