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absent FHR variability
lack of FHR baseline fluctuation
abrupt increases in the FHR above the baseline 15 bpm or more lasting 15 seconds or more
FHR baseline less than 110 bpm lasting greater than 10 minutes
contraction frequency
how often the contractions are occurring, determined by measuring from the beginning of one contraction to the beginning of the next contraction
contraction length
how long the contraction lasts, determined by measuring the time between the beginning of the contraction to the end of the contraction
contraction strength
intensity of the contraction, determined externally by palpation or internally by the intrauterine pressure catheter
early decelerations
usually, symmetrical, gradual FHR declines that then return to baseline, mirroring the uterine contraction
fetal heart rate (FHR)
heart rate and rhythm of the fetus
fetal reserve
fetus’s capacity to tolerate the normal intermittent interruptions in oxygenation during labor and recover back to full oxygenation
fetal scalp electrode (FSE)
affixed to the scalp of the fetus and provides close monitoring of the fetal heart rate
FHR baseline
average beats per minute in a 10-minute segment, excluding periodic changes or marked variability
FHR variability
beat-to-beat fluctuations in the FHR baseline
intermittent auscultation (IA)
technique of assessing fetal well-being by listening to and counting the fetal heart rate for a specified amount of time and at specified intervals, depending upon the stage of labor
intrauterine pressure catheter (IUPC)
device placed between the uterus and fetus that measures the exact pressure inside the uterus at rest and during contractions
intrauterine resuscitation
specific interventions aimed at increasing oxygen to the placenta and to the umbilical cord to reverse fetal hypoxia
late decelerations
symmetrical, gradual decreases in FHR after the start of a uterine contraction, with return to baseline after the ending of the contraction
marked FHR variability
FHR baseline fluctuation greater than 25 bpm
minimal FHR variability
FHR fluctuations of 5 bpm or fewer
mm Hg
millimeters of mercury, abbreviated mm Hg; measurement unit of intrauterine pressure catheter
moderate FHR variability
FHR fluctuations between 6 and 25 bpm
Montevideo unit
unit of measurement of uterine contraction strength via IUPC
periodic changes in the FHR
accelerations and decelerations of the FHR, abrupt or gradual, in relation to the FHR baseline
prolonged decelerations
isolated, sporadic decelerations of at least 15 bpm from the FHR baseline that last 2 to 10 minutes from onset to return to baseline
FHR baseline greater than 160 bpm
device that detects the frequency of uterine contractions
uterine contraction (UC)
tightening and shortening of the uterine muscles
uteroplacental insufficiency
disruption of the delivery of oxygen and nutrients to the fetus from the placenta
variable decelerations
abrupt decelerations of the FHR of at least 15 bpm below the baseline that last at least 15 seconds and less than 2 minutes, regardless of any uterine contraction

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