via model-based analyses maternal heart rate synchronization - Testing foetal

Potsdam Institute for Climate Impact Research, 14412 Potsdam, GermanyThe investigation of foetal reaction to internal and external conditions and stimuli is animportant tool in the characterization of the developing neural integration of the foetus.An interesting example of this is the study of the interrelationship between the foetal andthe maternal heart rate. Recent studies have shown a certain likelihood of occasionalheart rate synchronization between mother and foetus. In the case of respiratory-inducedheart rate changes, the comparison with maternal surrogates suggests that the evidencefor detected synchronization is largely statistical and does not result from physiologicalinteraction. Rather, they simply reflect a stochastic, temporary stability of twoindependent oscillators with time-variant frequencies. We reanalysed three datasetsfrom that study for a more local consideration. Epochs of assumed synchronizationassociated with short-term regulation of the foetal heart rate were selected and comparedwith synchronization resulting from white noise instead of the foetal signal. Using data-driven modelling analysis, it was possible to identify the consistent influence of theheartbeat duration of maternal beats preceding the foetal beats during epochs ofsynchronization. These maternal beats occurred approximately one maternal respiratorycyclepriortotheaffectedfoetalbeat.Asimilareffectcouldnotbefoundintheepochswithoutsynchronization. Simulations based on the fitted models led to a higher likelihood ofsynchronization in the data segments with assumed foetal–maternal interaction than inthe segment without such assumed interaction. We conclude that the data-driven model-based analysis can be a useful tool for the identification of synchronization.