deceleration(redirected from variable d)
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the sudden stopping of movement, a frequent mechanism of motion injury. Common causes of deceleration injury are motor vehicle accidents and falls.
early deceleration in fetal heart rate monitoring, a transient decrease in heart rate that coincides with the onset of a uterine contraction.
late deceleration in fetal heart rate monitoring, a transient decrease in heart rate occurring at or after the peak of a uterine contraction and resulting from fetal hypoxia.
variable d's in fetal heart rate monitoring, a transient series of decelerations in heart rate that vary in duration, intensity, and relation to uterine contractions; they are abrupt in onset and cessation and result from vagus nerve firing in response to stimuli such as umbilical cord compression in the first stage of labor.
1. The act of decelerating.
2. The rate of decrease in velocity per unit of time.
decelerationDip Obstetrics A periodic & transient slowing of the fetal heart rate in response to uterine contractions, ie stress. See Fetal heart monitor, Uniform deceleration, Variable deceleration.
Uniform deceleration The fetal heart response to uterine contractions; UCs are symmetrical, have a uniform temporal relation thereto and are divided into:
Early deceleration/Type I dip Due to vagal stimulation elicited in the first stage of labor by fetal head compression
Late deceleration/Type II dip Due to uteroplacental insufficiency, potentially associated with a less favorable outcome; may signal early vasomotor lability
Variable deceleration The fetal heart response is asynchronous with respect to uterine contractions; the curves on the fetal heart monitor are more angled and saw-toothed, and may be related to compromise in placental blood flow, eg umbilical cord compression and, like late decelerations, may signify parturition-related difficulties
1. A slowing of contractions during the first stage of labor.
2. A slowing of the fetal heart rate during uterine contractions.
[de- + acceleration]
A decrease in the fetal heart rate that can indicate inadequate blood flow through the placenta.
Mentioned in: Antepartum Testing
A slowing of contractions during the first stage of labor.
[de- + asceleration]