Intrapartum fetal monitoring: past, present, and future.

The concept of intrapartum "monitoring" of the fetal heart rate by auscultation has been extant for almost 200 years and by electronic means for more than 30 years. This article explores historical aspects of fetal monitoring, the advent of electronic fetal monitoring and its controversies, and present and future research opportunities to enhance the reliability, validity, and efficacy of fetal monitoring.