Intrapartum fetal heart rate monitoring

The risk of fetal hypoxia during labour and delivery is far higher than in a similar period in the third trimester of pregnancy. Especially during the second stage of labour the fetus has an increased risk of suffering from hypoxia/asphyxia/acidosis. Particularly the development of neonatal seizures in the first 1-2 days following birth is an unfavourable sign for functioning in later life. Absence of accelerations and minimal or absent variability are prominent signs in infants who develop acidosis, followed by seizures in the neonatal period. A number of societies have provided guidelines on who, when and how to monitor the condition of the fetus during the process of labour and delivery. The choice mostly is between intermittent auscultation and electronic FHR monitoring. In some guidelines, electronic FHR monitoring is not a required standard, even for high-risk patients. Nevertheless few practitioners or hospitals have removed cardiotocographs from their labour and delivery units. The recommendation to leave the choice between intermittent auscultation and electronic FHR monitoring to the labouring woman and her attending clinician is based on the conclusions from meta-analyses summarizing outcomes and interventions in randomized controlled trials. Most randomized controlled trials (RCTs) were performed during the 1970s and 1980s. They comprise a mixture of low- and high-risk patients, and preterm and term labours. The studies lack information on how electronic FHR monitoring was performed. Allocation to either intermittent auscultation or electronic FHR monitoring has been variable. The outcome parameters varied likewise. Nearly all RCTs would not fulfil current standards for the quality of a randomised controlled trial. It is a general belief that the FHR tracings obtained with the external mode of FHR monitoring are of a quality comparable to the internal mode. Rupture of the membranes is considered unnecessary to generate a good quality trace. These opinions leading to false trust and the neglect of obtaining good quality traces are not supported by data from our own hospital. In singletons and especially in twins, internal FHR monitoring provides far better data than the external mode. (c) 2005 Published by Elsevier B.V.