Fetal heart rate development during labour

Abstract

Background Fresh stillbirths (FSB) and very early neonatal deaths (VEND) are important global challenges with 2.6 million deaths annually. The vast majority of these deaths occur in low- and low-middle income countries. Assessment of the fetal well-being during pregnancy, labour, and birth is normally conducted by monitoring the fetal heart rate (FHR). The heart rate of newborns is reported to increase shortly after birth, but a corresponding trend in how FHR changes just before birth for normal and adverse outcomes has not been studied. In this work, we utilise FHR measurements collected from 3711 labours from a low and low-middle income country to study how the FHR changes towards the end of the labour. The FHR development is also studied in groups defined by the neonatal well-being 24 h after birth. Methods A signal pre-processing method was applied to identify and remove time periods in the FHR signal where the signal is less trustworthy. We suggest an analysis framework to study the FHR development using the median FHR of all measured heart rates within a 10-min window. The FHR trend is found for labours with a normal outcome, neonates still admitted for observation and perinatal mortality, i.e. FSB and VEND. Finally, we study how the spread of the FHR changes over time during labour. Results When studying all labours, there is a drop in median FHR from 134 beats per minute (bpm) to 119 bpm the last 150 min before birth. The change in FHR was significant ($$p<0.05$$ p < 0.05 ) using Wilcoxon signed-rank test. A drop in median FHR as well as an increased spread in FHR is observed for all defined outcome groups in the same interval. Conclusion A significant drop in FHR the last 150 min before birth is seen for all neonates with a normal outcome or still admitted to the NCU at 24 h after birth. The observed earlier and larger drop in the perinatal mortality group may indicate that they struggle to endure the physical strain of labour, and that an earlier intervention could potentially save lives. Due to the low amount of data in the perinatal mortality group, a larger dataset is required to validate the drop for this group.

Fetal to Neonatal Heart Rate Transition during Normal Vaginal Deliveries: A Prospective Observational Study

“…The dataset used in this work was from the Liveborn database and collected between 1 October 2020 and 30 August 2021. The FHR data from Moyo were cleaned using a previously proposed framework by Urdal et al [ 15 ]. Segments of less than 30 s were removed, as the HR was considered unlikely to belong to the fetus, but rather the mother.…”

“…Segments of less than 30 s were removed, as the HR was considered unlikely to belong to the fetus, but rather the mother. More information on the method and chosen segment length to be removed can be found in the article by Urdal et al [ 15 ].…”

“…The set baseline FHR of 110–160 bpm needs further investigation, especially during the second stage of labor. Few old and recent studies have attempted to describe baseline HR changes that occur during the transition at normal delivery [ 14 , 15 ]. An old study described that HR undergoes wide fluctuations during the transition at delivery [ 14 ].…”

“…An old study described that HR undergoes wide fluctuations during the transition at delivery [ 14 ]. Additionally, a recent study evaluated FHR close to the time of delivery and showed that the baseline FHR decreases significantly toward the time of delivery [ 15 ]. However, the latest study did not take into account the mode of delivery, even though changes in FHR are known to influence the mode of delivery [ 16 ].…”

Resuscitation of term and near-term newborns in low-resourced settings: Studies of positive end-expiratory pressure and expired CO2 during bag-mask ventilation at birth

“…Papers published by the group range from epidemiological studies and studies to evaluate cost effectiveness of interventions 192,[225][226][227][228][229] via studies of machine learning for automatic interpretation of data [230][231][232] to studies to describe practise, 196 evaluate effect of training methodologies, [233][234][235][236] studies to improve understanding of the basic physiology of newborn transition and resuscitation 74,134,138,221,237 and RCTs to compare new equipment to existing standards. 238,239…”