Institute of Medicine Outlines Priorities for Comparative Effectiveness Research

Abstract

fetal acid-base status; there isnotyet evidence to classify them as either normal or abnormal. Maconesnotedthis3-tierclassification systemisbasedonexpertopinion,notrigorousscientificevidence.“Despitethefact that it is used in 85% of births, there has been no new research in the last decade on fetal heart monitoring, so our document calls for more research,” he said. Such research appears long overdue. Macones and colleagues wrote that there are no randomized controlled trials comparing the benefits of electronic fetal monitoring with other forms of observation during labor and that benefits attributed to the technique are based on studies comparing it with intermittent fetal heart rate auscultation. Such studies indicate that electronicmonitoring,when compared with auscultation, reduces the risk of neonatal seizures. However, electronic fetal monitoring also increased the overall cesarean delivery rate as well as the risk of use of both vacuum and forceps operative techniques during a vaginal delivery, without reducing perinatal mortality or the risk of cerebral palsy. In addition, the false-positive rate of electronic monitoring for predicting cerebral palsy is greater than 99%, the guideline authors said. As for interpreting fetal heart rate tracings, Macones said work is needed to decrease variability and increase accuracy. The ACOG’s revision cited 1 study in which 4 obstetricians independently examined 50 tracings and reached similar interpretations in only 22% of the cases; 2 months later, in a review of the same 50 tracings, the obstetricians’ second interpretation differed from their initial evaluation in 21% of the tracings (Nielsen PV et al. Acta Obstet Gynecol Scand. 1987;66[5]:421-424). Thesamestudy foundthat reinterpretation of fetal heart rate tracings is subject to bias based on outcomes. The researchers foundthatareviewerwasmore likelytofindevidenceoffetalhypoxiaand tocriticizeanobstetrician’smanagement of the labor and delivery if the outcome for the fetuswaspoor insteadofgood.