Prolonged decelerations are caused by a disruption in the fetal oxygen supply. They usually begin as a reflex response to hypoxia. If the disruption continues, then the fetal cardiac tissue, itself, will become hypoxic, resulting in direct myocardial depression of the FHR.
What is prolonged deceleration?
Prolonged deceleration : A decrease in FHR of > 15 beats per minute measured from the most recently determined baseline rate. The deceleration lasts >= 2 minutes but less than 10 minutes. These decelerations appear to be mediated by arterial chemo receptors in mild hypoxia. What is fetal deceleration?
What causes prolonged deceleration during labor?
For example, repetitive prolonged decelerations may indicate cord compression from oligohydramnios. Even more troubling, a prolonged deceleration may occur for the first time during the evolution of a profound catastrophe, such as amniotic fluid embolism or uterine rupture during vaginal birth after cesarean delivery (VBAC).
What are the complications of late deceleration?
Complications arising from repeated or prolonged late decelerations include: A low APGAR (i.e., appearance, pulse, grimace, activity, and respiration) score A multidisciplinary team of health care professionals manages the process of labor and delivery for you.
What is an early deceleration?
An early deceleration is defined as a waveform with a gradual decrease and return to baseline with time from onset of the deceleration to the lowest point of the deceleration (nadir) >30 seconds.
What is considered prolonged deceleration?
Prolonged deceleration. A decrease in FHR below the baseline of 15 bpm or more, lasting at least 2 minutes but <10 minutes from onset to return to baseline. A prolonged deceleration of 10 minutes or more is considered a change in baseline.
What causes fetal deceleration?
Early decelerations are caused by fetal head compression during uterine contraction, resulting in vagal stimulation and slowing of the heart rate.
How do you find prolonged decelerations?
Prolonged deceleration : A decrease in FHR of > 15 beats per minute measured from the most recently determined baseline rate. The deceleration lasts >= 2 minutes but less than 10 minutes.
What are risk factors for late decelerations?
Causes of “late decelerations” or the drop in heart rate with uterine contraction are known to be : uteroplacental insuffiency ( not enough oxygen to the baby), amniotic fluid infection which can occur due to excessively long labor is permitted after the water has been broken, low maternal blood pressure, complications ...
What causes late deceleration?
Usually, any process that causes the following conditions is capable of inducing late decelerations: 1 Maternal low blood pressure (or hypotension) 2 Excessive activity in your uterus 3 Reduced oxygen supply to your placenta
What happens when you have late decels?
However, when late decels occur in more than 50 percent of the contractions of your uterus, then fetal hypoxia is a plausible explanation. Your doctor will then take action to prevent medical complications for your newborn.
What does it mean when your heart rate drops after labor?
Believed to be an abnormal FHR pattern, late decelerations indicate a reduction in heart rate, usually after a uterine contraction. Once deceleration starts, it takes about 20 to 30 seconds to reach its lowest point.
Why is my placenta decelerating?
Reduced oxygen supply to your placenta. Two of the most common late deceleration causes include an overactive uterus and hypotension due to epidural analgesia. This is the injection of an anesthetic into your spinal epidural space to eliminate pelvic pain during labor and delivery.
How long does it take for a deceleration to reach its lowest point?
Once deceleration starts, it takes about 20 to 30 seconds to reach its lowest point. When the timing of deceleration is delayed, it means that the lowest point is occurring past the peak of your uterine contraction. In the majority of cases, the beginning, low point, and recovery of late decelerations happen after the start, peak, ...
Is late deceleration dangerous?
One of many unusual FHR patterns observed during labor, late decelerations could be considered dangerous. They’re a sign of hampered blood flow to your placenta, which might trigger imminent fetal hypoxia (or a lack of oxygen for fetal tissues).
Accelerations vs. Decelerations
Accelerations are short-term increases in fetal heart rate by at least 15 beats per minute (bpm) that last at least 15 seconds. These accelerations occur at different times throughout labor and delivery and are a sign that the fetus has an adequate supply of oxygen.
Types of Deceleration
There are three types of deceleration that may occur during labor. Each type is categorized by the timing of the deceleration during uterine contractions. 1
What Causes Deceleration?
The cause of deceleration varies depending on the type. For example, early decelerations are caused by the compression of the baby’s head during uterine contractions. The compression causes vagal stimulation, which slows the fetal heart rate.
The Benefits and Risks of Fetal Monitoring
Electronic fetal heart rate monitoring can be used to evaluate the overall health of the fetus during labor. The primary benefit of monitoring is early detection of fetal distress, but there is also a risk of false-positive interpretations of the readings (also called tracings).
Frequently Asked Questions
Deceleration has various causes, depending on the type. For example, late decelerations (a drop in the fetal heart rate after uterine contractions) are caused by a decrease in the placental blood flow. This results in insufficient oxygen supply to the fetus (uteroplacental insufficiency). 2
