Meta-Analysis concludes benefits of ST Analysis

The objective of this meta-analysis, which includes five randomised trials (RCT) and 15,352 patients, was to compare the effects of adding ST Analysis to conventional intrapartum CTG. The included RCT’s evaluated singleton term pregnancies in cephalic presentation and the meta-analysis was performed on results for metabolic acidosis, fetal blood sampling, mode of delivery, Apgar score and neonatal care. For three of the studies, published corrected data were used and the meta-analysis could be performed on all data according to the intention-to-treat principle.

The random effects model* was used to estimate the combined relative risk. A relative risk less than 1 indicates an effect in favour for ST Analysis.







In previously reported meta-analysis’ in the Cochrane Database, fixed-effects analysis have been used. When this model was used for the five RCTs with converted data, the reduction in metabolic acidosis became significant.

The authors conclude that intrapartum monitoring with ST Analysis is a safe method and that its implementation can lead to a reduction in operative deliveries as well as the need for fetal blood sampling. The incidence of metabolic acidosis is reduced across a majority of the studies but reaches significance only when the fixed effects model is used. Due to the among-study differences on the effect of metabolic acidosis, the authors question if this is the right outcome to investigate, but other more specific perinatal outcomes are however very rare. They also conclude that since ST Analysis reduces both the intervention rate for suspect fetal distress and the total intervention rate, this indicates that ST Analysis has a true effect on the mode of delivery and lowers the risk of operative delivery.

*A random-effects model use estimates of the within study variances as well as estimates of the among study variances.


Abstract -Becker et al. 2012


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