Fetal pulse oximetry for fetal assessment in labour
Background Pulse oximetry could contribute to the evaluation of fetal well-being during labour. Objectives Objectives To compare the effectiveness and safety of fetal pulse oximetry with conventional surveillance techniques. Search methods Search methods We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2010), MEDLINE (1994 to May 2010), EMBASE (1994 to May 2010), Current Contents (1994 to May 2010) and contacted experts in the field. Selection criteria Selection criteria All published and unpublished randomised controlled trials that compared maternal and fetal outcomes when fetal pulse oximetry was used in labour, with or without concurrent use of conventional fetal surveillance, compared with using cardiotocography (CTG) alone. Data collection and analysis Data collection and analysis At least two independent authors performed data extraction. We performed analyses on an intention-to-treat basis. We sought additional information from the investigators of three of the reported trials. Main results Main results We included six published trials comparing fetal pulse oximetry and CTG with CTG alone (or when fetal pulse oximetry values were blinded). The published trials, with some unpublished data, reported on a total of 7654 pregnancies. Differing entry criteria necessitated separate analyses, rather than meta-analysis of all trials.Systematic review of four trials from 34 weeks not requiring fetal blood sampling prior to study entry showed no significant differences in the overall caesarean section rate between those monitored with fetal oximetry and those not monitored with fetal pulse oximetry or for whom the fetal pulse oximetry results were masked (risk ratio (RR) 0.99, 95% confidence intervals (CI) 0.86 to 1.13, n = 4008). Neonatal seizures and neonatal encephalopathy were rare. No studies reported details of assessment of long-term disability.There was a statistically significant decrease in caesarean section for nonreassuring fetal status in the fetal pulse oximetry plus CTG group compared to the CTG group, gestation from 34 weeks (RR 0.65, 95% CI 0.46 to 0.90). There was no statistically significant difference in caesarean section for dystocia when fetal pulse oximetry was added to CTG monitoring, compared with CTG monitoring alone, although the incidence rates varied between the trials. Authors' conclusions Authors' conclusions The data provide limited support for the use of fetal pulse oximetry when used in the presence of a nonreassuring CTG, to reduce caesarean section for nonreassuring fetal status. The addition of fetal pulse oximetry does not reduce overall caesarean section rates. A better method to evaluate fetal well-being in labour is required.