What causes reduced variability on CTG?

What causes reduced variability on CTG?

Reduced variability can occur due to central nervous system hypoxia/acidosis and resulting decreased sympathetic and parasympathetic activity, but it can also be due to previous cerebral injury [23], infection, administration of central nervous system depressants or parasympathetic blockers.

What causes decreased fetal variability?

Among the disorders associated with decreased FHR variability during labor are fetal asphyxia and acidosis and subsequent distress in the newborn. Among the factors that influence FHR variability are maternal fever, fetal immaturity, so-called fetal sleep, fetal tachycardia, and drug administration to the mother.

What does reduced variability mean CTG?

Reduced variability 3-5 beats per minute • Absent variability <3. beats per minute • Increased (salutatory) variability > 25 beats per minute. Accelerations are transient increases in FHR of 15bpm or more above the baseline and lasting 15 seconds.

What is baseline variability in Ctg?

Baseline FHR variability is defined as fluctuations in the baseline FHR that are irregular in amplitude and frequency. The fluctuations are visually quantitated as the amplitude of the peak-to-trough in beats per minute.

What factors affect HRV?

Physiological factors that influence your heart rate and HRV include age, gender, and circadian rhythm. Your HRV must be taken into account in short time measurements ranging from a few minutes to a few hours. While you sleep your HRV increases and decreases significantly in the hours just before you wake up.

How is normal baseline variability generated?

However, autonomic impulses immediately and constantly take effect changing the beat intervals and immediately altering the heart rate. This is how baseline variability is generated and it indicates integrity of the autonomic nervous system (Fig. 4.2).

What causes baseline variability?

Marked variability in the baseline FHR is present when the amplitude exceeds 25 BPM. This pattern (sometimes called a saltatory pattern) suggests acute hypoxia or mechanical compression of the umbilical cord and is often seen during the second stage of labor.

What causes low baseline fetal heart rate?

The most common causes of intrapartum bradycardia include poor uterine perfusion, maternal hypotension (e.g. after epidural placement), umbilical cord prolapse or occlusion, rapid fetal descent, tachysystole, placental abruption, or uterine rupture.

What does less variability mean?

When a distribution has lower variability, the values in a dataset are more consistent. However, when the variability is higher, the data points are more dissimilar and extreme values become more likely.

What is reduced variability?

Variability Reduction is a multi-part strategy to reduce product variation and make a product more robust or fit to use, e.g., meet its performance requirements regardless of variation. Design of Experiments (DOE) can be used to counter all three sources of variation.

Why is my baseline HRV so low?

Emotional, financial, structural (cervical instability) or physical stress (real or imagined) causes the heart rate to increase. The fast heart rate results in the time between heart beats to be very small. This coupled with the fact that breathing is very shallow (chest breathing) results in a low HRV.

What is too low HRV?

A consistent baseline score of 70 or higher is associated with health; whereas levels between 50 and 70 are compromised health and diseases; whereas a regular HRV below 50 puts the person at risk for catastrophic illness and even death.

What are the causes of decreased variability in the CTG?

Other causes of decreased variability include: normal fetal sleep-wake pattern, prematurity and following maternal administration of certain drugs including opioids. Accelerations are periodic, transient increases in FHR, defined as an increase in FHR >15 bpm for more than 15 seconds When accelerations are present, the CTG is said to be reactive.

What is a complicated variable deceleration CTG?

‘complicated’. Complicated variable decelerations are defined by their features as well as the other features of the CTG. These additional features indicate the likelihood of fetal hypoxia and the definition includes one or more of the following: o Rising baseline rate or fetal tachycardia o Reduced or absent baseline variability

What does the baseline mean in a CTG?

• The first thing we see in a CTG is the baseline . • In a CTG we see periodic accelerations and decelerations . • The baseline fhs is the rate between periodic changes. • Baseline is influenced by gestation and it’s higher in pre term. • BUT, at 28 weeks FHS is only 10 bpm higher than term.

What does a normal antenatal CTG trace look like?

Normal antenatal CTG trace: The normal antenatal CTG is associated with a low probability of fetal compromise and has the following features: Baseline fetal heart rate (FHR) is between 110-160 bpm Variability of FHR is between 5-25 bpm Decelerations are absent or early