The Significance of the Changes in the Continuous Fetal Heart Rate in the First Stage of Labour

Abstract

AND SummaryA comparison between data derived from changes in fetal heart rate and p H of fetal blood in 279 high-risk patients is described. 'The incidence of fetal acidosis was low when the continuous record of FHR showed good beat-to-beat variation in rhythm and no slowing during uterine contractions. The incidence of fetal acidosis accompanying fetal tachycardia or bradycardia was low if the rate remained unaltered during contractions. Decelerations of fetal heart rate accompanied by baseline tachycardia and/or loss of beat-to-beat variation were the changes most commonly associated with fetal acidosis and hence, by inference, with fetal asphyxia. Deep and/or delayed decelerations were also suggestive of fetal asphyxia. Late decelerations, although at first sight innocuous, were frequently found to be a sign of severe fetal asphyxia.

Fetal heart rate deceleration index — Its relation with fetal pH, Apgar score and dips or decelerations

“…d) The amplitude of the transitory descent of the FHR expressed in beats per minute [4,6]. We have proposed [1] that the deceleration index be calculated individually for every descent of the FHR, by adding the four above parameters and dividing the result by 10 to obtain a smaller numerical value easy to use.…”

“…dip 0300-5577/79/0007-0007$02.00 © by Walter de Gruyter & Co. · Berlin · New York area- [14,17], or by measuring the residual area [16]. CALDEYRO et al [6] established the relation between the "amplitude units" of the dip II and the APGAR score of the newborn, and BEARD et al [4] obtained a relationship that was not significant between the pH of the fetal blood and the lag time, and a less significant relationship between the pH and the amplitude of the decelerations. We are tryingtointroduceanewindex-Deceleration Index-[1] which is objective, easy to use and with which it is possible to give a numerical value to every transitory descent of the FHR in any of itsforms: early, late, variable or intermediate.…”

Neonatal outcome of suspected fetal distress cases

“…The diagnosis is usually based on characteristic changes in fetal heart rate assessed by auscultation or electronic recording with, in some cases, low pH in a fetal blood sample [1][2][3] . Suspected fetal distress during labour is always considered an emergency.…”

Recognition and significance of maternogenic fetal acidosis during intensive monitoring of labor

“…The good clinical condition of these The problem of choosing between these two infants at birth (APGAR ^ 7) indicates that rapid methods for routine use now seems to have been extraction of the fetus is not justified in such cases. solved; it has become clear that the two are A number of methods have been proposed for the mutually complementary [3,9,14,15,31,34,42]. recognition of this type of acidosis during labor, In general, the purpose of FBS and fetal pH but certain questions regarding the validity of determination is to reduce the margin of error these methods and their ability to meet the partiinherent in assessing the fetal condition by means cular clinical requirements of the delivery room of the cardiotachometer tracing.…”

“…The clinical and [2,19,26,28,31] are still unanswered. The data acid-base Status of the infant at birth may in fact be presented below were compiled at the First Clinic good, not only when the FHR has remainded of Obstetrics and Gynecology of the Milan Uninormal during labor (regulär, or with early versity during the period 1968-1972. deceleration), but also in a high percentage of cases showing abnormal or even highly abnormal l Cases and methods deceleration (late deceleration) [3,12,22,27,31,59 normal cases (normal pregnancy, normal onset 34,42].…”