Perinatal and Neonatal Outcomes Using Cardiotocography Versus STAN and Cardiotocography: a Systematic Review.

ST waveform analysis (STAN) was introduced to improve the interpretation of cardiotocography (CTG) resulting in reduction of unnecessary interventions and metabolic acidosis. A systematic review was conducted with the aim to evaluate the effect of STAN method compared with isolated CTG on perinatal and neonatal outcomes. A search of electronic databases (PubMed, Cochrane, Scopus) was conducted to identify randomized controlled trials (RCTs) in English language. Outcomes considered operative deliveries, fetal blood sampling (FBS), metabolic acidosis, perinatal and neonatal death, neonatal seizures, neonatal encephalopathy, transfer to the neonatal intensive care unit (NICU) and Apgar score. Seven RCTs were included in the present review. The first two RCTs showed that the combination of STAN and CTG was a better option than using CTG alone, because there was a documented reduction in the rate of operative deliveries due to fetal distress and metabolic acidosis. The following studies showed no statistically significant changes with the combination of methods, except from a reduction in FBS. The findings from the RCTs were inconclusive. Most studies did not demonstrate a superiority of the combination regarding operative deliveries and neonatal outcomes but there were many methodological differences between the trials.