IN RECENT YEARS advances and refinements in the capabilities of complex electronic equipment have given great impetus to the study of the physiology of pregnancy. Most investigators have concentrated their efforts on specific areas of uterine or fetal physiology. At Indiana University Medical Center a primary effort has been the study of relationships between fetal heart rate and intrauterine pressure during labor.
Fetal prognosis has long been based on fetal heart rate; however, the clinical practice of determining fetal heart rate by auscultation and averaging beats for a period of time does not reflect beat-to-beat variations. Continuous auscultation is impractical because of the interference created by uterine contractions and movement of the abdominal musculature.
Many investigators have utilized methods of indirect fetal electrocardiography, and by plotting fetal heart rate as related to uterine contractions, they have added significantly to the knowledge of fetal cardiac function during labor. Such electrocardiograms, obtained
Barden TP, Stander RW. Intrauterine Pressure and Fetal Heart Rate in Labor. JAMA. 1963;186(10):923-925. doi:10.1001/jama.1963.63710100007013b