Increased variability of fetal heart rate during labour: a review of preclinical and clinical studies. (5th June 2022) - Tarvonen, Mikko J.
Abstract: Increased fetal heart rate variability (FHRV) in intrapartum cardiotocographic recording has been variably defined and poorly understood, limiting its clinical utility. Both preclinical (animal) and clinical (human) evidence support that increased FHRV is observed in the early stage of intrapartum fetal hypoxaemia but can also be observed in a subset of fetuses during the preterminal stage of repeated hypoxaemia. This review of available evidence provides data and expert opinion on the pathophysiology of increased FHRV, its clinical significance and a stepwise approach regarding the management of this pattern, and propose recommendations for standardisation of related terminology. Tweetable abstract: Increased fetal heart rate variability is parasympathetic‐mediated and is caused by acutely deteriorating placental function.