Intrapartum fetal pulse oximetry and fetal heart rate decelerations

Abstract

Modifications in FHR occur simultaneously with alterations in FSpO(2), although the latter do not persist in time. Different degrees of FSpO(2) seen prior to deceleration are an expression of fetal respiratory status.

Fetal pulse oximetry: Correlation with intrapartum fetal heart rate patterns and neonatal outcome

“…Puertas and colleagues designed a study to determine the behaviour of FSpO 2 during different patterns of FHR decelerations 6 . Additionally, for each deceleration analysed, they measured FSpO 2 at different instants of deceleration (2 and 1 min before the onset of deceleration, during progressive deceleration, maximum decrease, during recovery, 1 and 2 min after recovery of the deceleration).…”

“…2,30 Puertas and colleagues designed a study to determine the behaviour of FSpO2 during different patterns of FHR decelerations. 6 Additionally, for each deceleration analysed, they measured FSpO2 at different instants of deceleration (2 and 1 min before the onset of deceleration, during progressive deceleration, maximum decrease, during recovery, 1 and 2 min after recovery of the deceleration). They found that fetal oxygen saturation during the course of labor decreased significantly in parallel with the maximum decrease in decelerations and during recovery of heart rate, in all groups of decelerations they studied (early, variable, late, prolonged).…”

“…However, low specifity in spite of its high sensitivity, variable and inconsistent interpretation even by experts in this field, and being an indirect way of fetal assessment reduce its clinical efficacy. High rates of false positive findings of CTG have unfortunately led to increased rates of cesarean deliveries due to nonreassuring FHR patterns which are not always accurate indicators of fetal hypoxia 6,7 …”

“…High rates of false positive findings of CTG have unfortunately led to increased rates of cesarean deliveries due to nonreassuring FHR patterns which are not always accurate indicators of fetal hypoxia. 6,7 In fact, abnormal FHR patterns for which instrumental delivery or cesarean section are done constitute of just 50% of all fetal acidosis cases.…”

Twenty‐five years after the FIGO guidelines for the use of fetal monitoring: Time for a simplified approach?

“…Moreover, it is likely that more than one pathophysiologic event may be involved in vivo in the genesis of the majority of decelerations. Several reports have suggested that the most ominous variants are decelerations lasting for more than 5 minutes, irrespective of the type [18,19].…”