PLYMOUTH RANDOMIZED TRIAL OF CARDIOTOCOGRAM ONLY VERSUS ST WAVE-FORM PLUS CARDIOTOCOGRAM FOR INTRAPARTUM MONITORING IN 2400 CASES

OBJECTIVE: The physiology of changes in the ST waveform of the fetal e lectrocardiogram has been elucidated in extensive animal and human obs ervational studies. A combination of heart rate and ST waveform analys is might improve the predictive value of intrapartum monitoring. Our p urpose was to compare operative intervention and neonatal outcome in l abors monitored by the conventional cardiotocogram with those monitore d by ST waveform plus the cardiotocogram. STUDY DESIGN: A prospective, randomized clinical trial was performed on 2434 high-risk labors in a district general hospital in Plymouth, England. Statistical analysis was performed by Student t test and chi2 analysis. RESULTS: There was a 46% reduction (p < 0.001, odds ratio 1.85 [1.35-2.661) in operative deliveries for ''fetal distress'' and a trend to less metabolic acidos is (p = 0.09, odds ratio 0.38 [0.13-1.07]) and fewer low 5-minute Apga r scores (p = 0. 1 2, odds ratio 0.62 [0.35-1.081) in the ST waveform plus cardiotocogram arm. CONCLUSIONS: ST waveform analysis discriminat es cardiotocogram changes in labor, and the protocol for interpretatio n is safe. Further randomized studies are warranted.