Quantitative cardiotocography to improve fetal assessment during labor: a preliminary randomized controlled trial

Abstract

ObjectiveTo evaluate the effectiveness of a computerized decision support system, referred to as “quantitative cardiotocography” (qCTG), to reduce adverse birth outcomes compared to conventional CTG with fetal blood sampling. Study designA preliminary parallel randomized control trial in a tertiary maternity hospital (Sofia, Bulgaria) was conducted with a sample size of 360 women per trial arm (N=720). Women in labor were recruited between March 2008 and March 2011. Unadjusted relative risks were derived to assess the effect of qCTG on outcomes of interest. A ROC curve was derived to determine the sensitivity and specificity of qCTG to detect acidemia (Clinical trial registration: Current Controlled Trials, http://www.controlled-trials.com/, ISRCTN46449237). Main outcome measuresPrimary outcomes were hypoxia (cord-artery blood pH<7.20), acidemia (umbilical-artery blood pH<7.05), cesarean delivery, and forceps extraction. Secondary outcomes were Apgar score <7 at five minutes, neonatal seizures, and admission to the neonatal intensive care unit (NICU). ResultsReduced risks were observed for all outcomes of interest in women monitored using qCTG. There was a significant reduction in hypoxia (RR: 0.53; 0.33, 0.84), acidemia (RR: 0.31; 95% CI: 0.12, 0.84), cesarean delivery (95% CI: 0.45, 0.85), and admission to the NICU (RR: 0.33; 95% CI: 0.14, 0.77) in women monitored using qCTG versus conventional CTG. ConclusionqCTG may reduce risk of adverse birth outcomes; however, the small sample size and long recruitment period in this trial may overstate the benefits of this intervention. Further large-scale randomized control trials with sufficient sample size to detect rare adverse events are required prior to the adoption of qCTG in daily clinical practice.