A randomised clinical trial of intrapartum fetal monitoring with computer analysis and alerts versus previously available monitoring

Abstract

BackgroundIntrapartum fetal hypoxia remains an important cause of death and permanent handicap and in a significant proportion of cases there is evidence of suboptimal care related to fetal surveillance. Cardiotocographic (CTG) monitoring remains the basis of intrapartum surveillance, but its interpretation by healthcare professionals lacks reproducibility and the technology has not been shown to improve clinically important outcomes. The addition of fetal electrocardiogram analysis has increased the potential to avoid adverse outcomes, but CTG interpretation remains its main weakness. A program for computerised analysis of intrapartum fetal signals, incorporating real-time alerts for healthcare professionals, has recently been developed. There is a need to determine whether this technology can result in better perinatal outcomes.Methods/designThis is a multicentre randomised clinical trial. Inclusion criteria are: women aged ≥ 16 years, able to provide written informed consent, singleton pregnancies ≥ 36 weeks, cephalic presentation, no known major fetal malformations, in labour but excluding active second stage, planned for continuous CTG monitoring, and no known contra-indication for vaginal delivery. Eligible women will be randomised using a computer-generated randomisation sequence to one of the two arms: continuous computer analysis of fetal monitoring signals with real-time alerts (intervention arm) or continuous CTG monitoring as previously performed (control arm). Electrocardiographic monitoring and fetal scalp blood sampling will be available in both arms. The primary outcome measure is the incidence of fetal metabolic acidosis (umbilical artery pH < 7.05, BDecf > 12 mmol/L). Secondary outcome measures are: caesarean section and instrumental vaginal delivery rates, use of fetal blood sampling, 5-minute Apgar score < 7, neonatal intensive care unit admission, moderate and severe neonatal encephalopathy with a marker of hypoxia, perinatal death, rate of internal monitoring, tracing quality, and signal loss. Analysis will follow an intention to treat principle. Incidences of primary and secondary outcomes will be compared between groups. Assuming a reduction in metabolic acidosis from 2.8% to 1.8%, using a two-sided test with alpha = 0.05, power = 0.80, and 10% loss to follow-up, 8133 women need to be randomised.DiscussionThis study will provide evidence of the impact of intrapartum monitoring with computer analysis and real-time alerts on the incidence of adverse perinatal outcomes, intrapartum interventions and signal quality. (Current controlled trials ISRCTN42314164)

Fetal Monitoring: Creating a Culture of Safety With Informed Choice

“…There were no differences in neonatal outcomes (East et al, 2006). STAN is another adjunct to EFM when hypoxia is suspected, and it increases the identification of fetuses with metabolic acidosis (Ayres-de-Campos et al, 2010). Because of different interpretations of EFM tracings, adverse neonatal outcomes continue to occur with STAN, with no difference in the perinatal mortality rate (Ayres-de-Campos et al, 2010) or significant differences in primary outcomes (Neilson, 2012).…”

“…Internal monitoring is added to EFM if fetal distress is suspected and includes fetal scalp blood sampling, fetal pulse oximetry, or ST segment analysis (STAN; Ayres-de-Campos, et al, 2010;East, Brennecke, King, Chan, & Colditz, 2006;Kale, Chong, & Biswas, 2008;Tekin et al, 2008).…”

FIGO consensus guidelines on intrapartum fetal monitoring: Adjunctive technologies

“…Studies with larger sample sizes and direct comparisons of the different systems are lacking. Two of these systems have recently completed multicenter RCTs comparing them with standard CTG analysis [71,72], and their results are expected soon.…”

An overview of central fetal monitoring systems in labour

“…The system is currently being evaluated in a randomised clinical trial that is taking place in the UK [6] .…”

“…FHR analysis is based on the International Federation of Obstetrics and Gynaecology (FIGO) guidelines for fetal monitoring, incorporating baseline estimation, identifi cation of accelerations and decelerations and evaluation of long-and short-term variability. The system provides real-time visual and sound alerts of different colour codes [5,6,12] . Combined alerts, integrating CTG and ST events, have also been incorporated based on the revised STAN guidelines [2] .…”