Computerised analysis of the fetal heart rate and relation to acidaemia at delivery.

Abstract

To identify the individual features of the computerised analysis of the cardiotocograph that relate to arterial pH and base deficit at delivery. Retrospective observational study. Teaching hospital labour wards. 679 women requiring continuous intrapartum fetal monitoring. Fetal heart and uterine contraction data were obtained using the Nottingham Fetal ECG monitor. Fetal heart rate patterns for the last half-hour preceding delivery were analysed using a computer algorithm developed for intrapartum application. The significance of the areas under receiver operator characteristic curves were calculated. Umbilical arterial pH and base deficit at delivery. Three parameters, fetal bradycardia, total deceleration area and the deceleration area after a contraction had receiver operator characteristic curves that significantly predict a low umbilical arterial pH and base deficit at delivery (areas under receiver-operator characteristic curves = 0.53, SD 0.01 P = 0.03; 0.60, SD 0.03 P = 0.002; 0.62 SD 0.04 P < 0.001, respectively). Tachycardia, accelerations and variability did not. The individual components of the computerised analysis of the fetal heart rate that predict acidaemia at delivery are identified.