Renewed meta-analysis: Further support for ST Analysis

The objective of this meta-analysis was to investigate the additional effect of ST Analysis as an adjunct to electronic fetal monitoring. In order to overcome the shortcomings of conventional meta-analysis that uses aggregated data, the present analysis used individual participant data to allow for a more thorough investigation by taking all information into account, including accounting for missing data.

Only four of the five published randomised controlled trials (RCT) were included in the analysis. The first RCT by Westgate et al. was excluded because the ST Analysis method used in that study was different from the method used in the more recent studies. Individual data from 6524 participants in the CTG+ST Analysis group and 6463 participants in the CTG group were included in the analysis.

The analysis was conducted on intention-to-treat basis and using the random effects model.

The authors comment that their meta-analysis gives a conservative result on the added value of ST Analysis as it did not include the Westgate et al. study which showed a significant decrease in metabolic acidosis. In addition, the analysis included imputation of missing values resulting in an addition of 7 (15%) metabolic acidosis case to the CTG+ST Analysis group and only 6 (9%) cases to the CTG group.

The analysis showed that CTG+ST Analysis lead to a reduction in the frequency of operative vaginal deliveries and fetal blood sampling. The incidence of metabolic acidosis was reduced by 25% but this was not statistically significant. The overall very low incidence of metabolic acidosis (1%) may be the result of better interpretation of CTG thanks to the use of the Stan Guidelines CTG interpretation in all patients and the required training before using ST Analysis.

1. Schuit et al. Effectiveness of electronic fetal monitoring with additional ST-analysis in vertex singleton pregnancies beyond 36 weeks of gestation: an individual participant data meta-analysis. Am J Obstet Gynecol 2013;208:187.e1-13


Abstract – Schuit et al. 2013

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