New Scientific Publication: No risk associated with high baseline T/QRS ratio
In the European Stan Expert meeting in 2009, the interpretation of a high baseline T/QRS ratio at the start of a registration was discussed since some cases with high baseline T/QRS followed by metabolic acidosis had been encountered. The baseline T/QRS is the absolute value of the T/QRS ratio at the start of a Stan recording, and is currently only used for comparison with later changes indicating a rise in the T-wave of the fetal ECG.The objective of this retrospective studywas to evaluate if the value of the baseline T/QRS ratio could be used to predict intrapartum asphyxia. High baseline T/QRS ratio was defined as ≥0.25 or ≥2 SD from the mean.
A total of 2459Stan recordings from two earlier published studies were included in the evaluation. The recordings were divided into three groups depending on outcome; 88.3% had an uncomplicated delivery, 8.9% ended in an operative delivery due to suspected fetal distress and 2.8% of the neonates had an adverse outcome. No statistically significant differences in mean T/QRS baseline could be identified between the three groups.
The authors state that they did not find any arguments in favour of using high baseline T/QRS at the start of the Stan recording as a predictor for adverse neonatal outcome or intervention for fetal distress. In addition they conclude that the current Stan guidelinesare still suitable, and that local Stan guidelines that are extended to include recommendations regarding high T/QRS baseline should be adjusted.
Abstract
Acta Obstet Gynecol Scand. 2012 Feb;91(2):189-197
Predictive value of the baseline T-QRS ratio of the fetal electrocardiogram in intrapartum fetal monitoring: a prospective cohort study.
OBJECTIVE:
To evaluate the added value of the baseline T/QRS ratio to other known risk factors in predicting adverse outcome and interventions for suspected fetal distress.
DESIGN:
Prospective cohort study.
SETTING:
Three academic and six non-academic teaching hospitals in the Netherlands. Population. Laboring women with a high-risk cephalic singleton pregnancy beyond 36 weeks of gestation. Methods. We obtained STAN® recordings (ST-analysis, Neoventa, Sweden) from two previous studies. Three patient groups were defined: cases with adverse outcome, cases with emergency delivery because of suspected fetal distress without adverse outcome, and a reference group of uncomplicated cases. Baseline T/QRS ratios among the adverse outcome and intervention for suspected fetal distress cases were compared to those of the uncomplicated cases. The ability of baseline T/QRS to predict adverse outcome and suspected fetal distress was determined using a multivariable logistic model.
MAIN OUTCOME MEASURES:
The added value of the baseline T/QRS to other known risk factors in the prediction of adverse outcome and interventions for suspected fetal distress.
RESULTS:
From 3462 recordings, 2459 were available for analysis. Median baseline T/QRS for uncomplicated cases, adverse outcome and interventions for suspected fetal distress were 0.12 (range 0.00-0.52), 0.12 (0.00-0.42) and 0.13 (0.00-0.39), respectively. There was no statistical difference between these groups. Multivariable analysis showed no added value of baseline T/QRS in the prediction of either adverse outcome or interventions for suspected fetal distress.
CONCLUSION:
Baseline T/QRS has no added value in the prediction of adverse neonatal outcome or interventions for suspected fetal distress.