A validation of electrohysterography for uterine activity monitoring during labour

Objectives. Validation of electrohysterography (EHG) as a method for uterine activity monitoring during labour by comparing with intra-uterine pressure catheter (IUPC) recordings. Design. Prospective observational study. Setting. Labour ward in a tertiary centre in the Netherlands. Population. Thirty-two women in labour. Methods. Simultaneous recording of uterine activity with EHG and IUPC for at least 30 min. Main outcome measures. Number of uterine contractions detected by both EHG and IUPC (sensitivity). Number of contractions detected by EHG only [positive predictive value (PPV)]. Correlation between contraction amplitude and duration measured by EHG and IUPC. Results. EHG detects uterine contractions accurately: sensitivity = 94,5% (95%CI: 87.5-100), PPV = 88.3% (95%CI: 76.2-100). The correlation of contractions' duration and amplitude between both methods is r = 0.31 (95%CI: 0.23-0.39) and r = 0.45 (95%CI: 0.38-0.52), respectively. Conclusions. EHG detects uterine contractions accurately during labour but the contraction's characteristics it measures are not directly comparable with that of IUPC.