History

   Until recently, as new technologies have emerged, they have been adopted into clinical practice before large studies were carried out regarding their efficacies. IA was widely used for four decades before the first randomized clinical trials (RCTs) and EFM was used over a decade before the first RCT was available.

   Many of the RCTs designed for EFM compare it to IA, though it should be remembered that Benson et al. were highly critical of IA in 1968. Cochrane has published a meta-analysis comparing EFM to IA which showed no difference between the two in low Apgar scores, NICU admissions, perinatal deaths, or the development of Cerebral Palsy (CP). There was a 50% reduction in neonatal seizures, but a significant increase in operative vaginal delivery and cesarean delivery rates. Vintzeileos et al did show a reduction in perinatal death in the EFM group as compared to IA, on the order of one perinatal death prevention for every 1000 births, but with an associated increase in the cesarean delivery rate of 2-3 fold. Notwithstanding these controversies, EFM continues to be widely used today as a routine monitor of fetal wellbeing.

   Despite the widespread use of electronic fetal monitors, uniformity of terminology and standards were not firmly established until 1997 when the American College of Obstetricians and Gynecologists (ACOG) and the Association of Women’s Health, Obstetric, and Neonatal Nurses (AWHONN) along with other professional organizations adopted the terminology of the National Institute of Child Health and Human Development (NICHD) Research Planning Workshop for use in describing fetal heart rate patterns. The terminology used in this website reflects those standards and terminology.

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