Comparing the effect of STan (cardiotocographic electronic fetal monitoring (CTG) plus analysis of the ST segment of the fetal electrocardiogram) with CTG alone on emergency caesarean section rates: study protocol for the STan Australian Randomised controlled Trial (START).

BACKGROUND: Cardiotocography is almost ubiquitous in its use in intrapartum care. Although it has been demonstrated that there is some benefit from continuous intrapartum fetal monitoring using cardiotocography, there is also an increased risk of caesarean section which is accompanied by short-term and long-term risks to the mother and child. There is considerable potential to reduce unnecessary operative delivery with up to a 60% false positive diagnosis of fetal distress using cardiotocography alone. ST analysis of the fetal electrocardiogram is a promising adjunct to cardiotocography alone, and permits detection of metabolic acidosis of the fetus, potentially reducing false positive diagnosis of fetal distress. METHODS: This study will be a single-centre, parallel-group, randomised controlled trial, conducted over 3 years. The primary hypothesis will be that the proportion of women with an emergency caesarean section on ST analysis will not equal that for women on cardiotocography monitoring alone. Participants will be recruited at the Women's and Children's Hospital, a high-risk specialty facility with approximately 5000 deliveries per annum. A total of 1818 women will be randomised to the treatment or conventional arm with an allocation ratio of 1:1, stratified by parity. The primary outcome is emergency caesarean section (yes/no). Statistical analysis will follow standard methods for randomised trials and will be performed on an intention-to-treat basis. Secondary maternal and neonatal outcomes will also be analysed. Additional study outcomes include psychosocial outcomes, patient preferences and cost-effectiveness. DISCUSSION: Approximately 20% of Australian babies are delivered by emergency caesarean section. This will be the first Australian trial to examine ST analysis of the fetal electrocardiogram as an adjunct to cardiotocography as a potential method for reducing this proportion. The trial will be among the first to comprehensively examine ST analysis, taking into account the impact on psychosocial well-being as well as cost-effectiveness. This research will provide Australian evidence for clinical practice and guideline development as well as for policy-makers and consumers to make informed, evidence-based choices about care in labour. TRIAL REGISTRATION: ANZCTR, ACTRN1261800006268 . Registered on 19 January 2018

Fetal electrocardiography in labor and neonatal outcome: Data from the Swedish randomized controlled trial on intrapartum fetal monitoring

OBJECTIVE: Cardiotocography plus automatic ST analysis of the fetal electrocardiography has been shown recently to reduce both the operative delivery rate for fetal distress and the cord artery metabolic acidosis rate. The purpose of this study was to analyze findings that were related to cases with a complicated/adverse neonatal outcome in the Swedish randomized controlled trial. STUDY DESIGN: Of the 4966 term fetuses that were included in the trial, all 351 newborn infants who required special neonatal care were identified. Cases of perinatal death, neonatal encephalopathy, or metabolic acidosis at birth were reviewed. RESULTS: Of the 29 fetuses with adverse/complicated neonatal outcome, 22 fetuses had cardiotocography and ST patterns that indicated a need for intervention, according to the cardiotocography plus ST clinical guidelines. The number of live-born with moderate or severe neonatal encephalopathy showed a significant decrease from 0.33% (8/2447 fetuses) in the cardiotocography-only group to 0.04% (1/2519 fetuses) in the cardiotocography plus ST group. CONCLUSION: Cardiotocography plus ST analysis provides accurate information about intrapartum hypoxia and may prevent intrapartum asphyxia and neonatal encephalopathy by giving a clear alert to the staff members who are in charge

United States multicenter clinical usage study of the STAN 21 electronic fetal monitoring system.

OBJECTIVE: The fetal electrocardiogram system for electronic fetal monitoring (EFM) (STAN S21, Neoventa Medical, Moelndal, Sweden) has led to improved perinatal outcomes in other countries. We aimed to assess the ability of United States (US) obstetricians to use this system appropriately for intrapartum care. STUDY DESIGN: A prospective nonrandomized trial was conducted in 6 sites. Enrollment required a singleton vertex fetus, >36 weeks' gestation, with indications for direct fetal monitoring during first stage of labor. Appropriate use was measured by negative predictive value (NPV) of nonintervention for fetuses with nonreassuring fetal heart rate (FHR) patterns, normal STAN readings, and normal neonatal outcomes with umbilical cord arterial pH >7.12; and percent agreement (PA) for intervention decisions with 3 STAN experts who conducted retrospective case reviews blinded to outcome. RESULTS: Five hundred and thirty patients were enrolled. An NPV of 95.2% was achieved while PA between investigators and STAN experts was 84%, and 90%, for intervention and nonintervention, respectively. No fetus with metabolic acidosis requiring intervention was missed by US clinicians. CONCLUSION: US clinicians used the STAN system appropriately in a manner similar to that of experienced STAN users

Cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram for intrapartum fetal monitoring: a Swedish randomised controlled trial.

BACKGROUND: Previous studies indicate that analysis of the ST waveform of the fetal electrocardiogram provides information on the fetal response to hypoxia. We did a multicentre randomised controlled trial to test the hypothesis that intrapartum monitoring with cardiotocography combined with automatic ST-waveform analysis results in an improved perinatal outcome compared with cardiotocography alone. METHODS: At three Swedish labour wards, 4966 women with term fetuses in the cephalic presentation entered the trial during labour after a clinical decision had been made to apply a fetal scalp electrode for internal cardiotocography. They were randomly assigned monitoring with cardiotocography plus ST analysis (CTG+ST group) or cardiotocography only (CTG group). The main outcome measure was rate of umbilical-artery metabolic acidosis (pH <7.05 and base deficit >12 mmol/L). Secondary outcomes included operative delivery for fetal distress. Results were first analysed according to intention to treat, and secondly after exclusion of cases with severe malformations or with inadequate monitoring. FINDINGS: The CTG+ST group showed significantly lower rates of umbilical-artery metabolic acidosis than the cardiotocography group (15 of 2159 [0.7%] vs 31 of 2079 [2%], relative risk 0.47 [95% CI 0.25-0.86], p=0.02) and of operative delivery for fetal distress (193 of 2519 [8%] vs 227 of 2447 [9%], 0.83 [0.69-0.99], p=0.047) when all cases were included according to intention to treat. The differences were more pronounced after exclusion of 291 in the CTG+ST group and 283 in the CTG group with malformations or inadequate recording. INTERPRETATION: Intrapartum monitoring with cardiotocography combined with automatic ST-waveform analysis increases the ability of obstetricians to identify fetal hypoxia and to intervene more appropriately, resulting in an improved perinatal outcome