Transcript A New Life

Jan Charmaine Almonte-Saret
M.D.FPOGS, FPSUOG
ELECTRONIC FHR MONITORING
•
Electronic fetal heart rate monitoring is
commonly used to assess fetal well-being
during labor.
• also risks, including false-positive tests that
may result in unnecessary surgical
intervention.
ELECTRONIC FHR MONITORING
 Fetal heart rate patterns are classified as
reassuring, nonreassuring or ominous.
 Differentiating between a reassuring and
nonreassuring fetal heart rate pattern is the
essence of accurate interpretation, which is
essential to guide appropriate triage decisions.
ACOG Recommendation for Continous EFM
Selected High-Risk Indications for Continuous Monitoring of Fetal Heart Rate
Maternal medical illness
Gestational diabetes
Hypertension
Asthma
Obstetric complications
Multiple gestation
Post-date gestation
Previous cesarean section
Intrauterine growth restriction
Premature rupture of the membranes
Congenital malformations
Third-trimester bleeding
Oxytocin induction/augmentation of labor
Preeclampsia
Psychosocial risk factors
No prenatal care
Tobacco use and drug abuse
Benefits of EFM
• detect early fetal distress resulting from fetal
hypoxia and metabolic acidosis.
• closer assessment of high-risk mothers.
• FHR assessment may be equal or superior to
measurement of fetal blood pH in the
prediction of both good and bad fetal outcomes.
RISKS OF EFM
• Variable and inconsistent interpretation of
tracings by clinicians may result in
unnecessary surgical intervention
• Internal monitoring may cause fetal scalp
infection
Interpreting FHR Patterns
Nonreassuring patterns
Ominous patterns
• Fetal tachycardia
• Persistent late
decelerations with loss of
beat-to-beat variability
• Nonreassuring variable
decelerations associated
with loss of beat-to-beat
variability
• Prolonged severe
bradycardia
• Sinusoidal pattern
• Confirmed loss of beat-tobeat variability not
associated with fetal
quiescence, medications or
severe prematurity
• Fetal bradycardia
• Saltatory variability
• Variable decelerations
associated with a
nonreassuring pattern
• Late decelerations with
preserved beat-to-beat
variability
Interpreting FHR Patterns
Causes of Fetal Tachycardia
Fetal hypoxia
Maternal fever
Hyperthyroidism
Maternal or fetal anemia
Parasympatholytic drugs
Sympathomimetic drugs
Chorioamnionitis
Fetal tachyarrhythmia
Prematurity
Interpreting FHR Patterns
Emergency Interventions for Nonreassuring Patterns
Call for assistance
Administer oxygen through a tight-fitting face mask
Discontinue oxytocin if used
Change maternal position to left lateral or knee-chest
Administer fluid bolus (lactated Ringer's solution)
Perform a vaginal examination and fetal scalp stimulation
When possible, determine and correct the cause of the pattern
Consider tocolysis (for uterine tetany or hyperstimulation)
Determine whether operative intervention is warranted and, if so, how
urgently it is needed
FHR Variability
 reflects a healthy nervous system,
chemoreceptors, baroreceptors and cardiac
responsiveness
 Prematurity ,fetal hypoxia, congenital heart
anomalies and fetal tachycardia decreases
variability
FHR Variability
 loss of beat-to-beat variability is more
significant than loss of long-term variability
and may be ominous
 Loss of variability may be uncomplicated
and may be the result of fetal quiescence
(rest-activity cycle or behavior state)
FHR Variability
 Uncomplicated loss of variability - CNS depressants
such as morphine, diazepam
and magnesium sulfate; parasym
patholytic agents (atro-pine and
hydroxyzine - Atarax); and centr
ally acting adrenergic agents suc
h as methyldopa (Aldomet)
 Decreased FHR variability in combination with late
or variable deceleration patterns - increased risk of
fetal pre-acidosis (pH 7.20 to 7.25) or aci
dosis (pH less than 7.20) and signifies
that the infant will be depressed at birth.2
1
FHR Variability
 combination of late or severe variable
decelerations with loss of variability
ominous.
 late or worsening variable deceleration pattern
in the presence of normal variability - the fetal
stress is either of a mild degree or of recent origin
however, considered nonreassuring.
FHR Patterns
Saltatory pattern with wide variability. The oscillations of
the fetal heart rate above and below the baseline exceed 25
bpm.
FHR Variability
 SSaltatory pattern - is usually caused by
acute hypoxia or mechanical compression of
the umbilical cord.
 most often seen during the second stage of
labor
 nonreassuring pattern, but usually not an
indication for immediate delivery
Fetal Tachycardia
• baseline heart rate > 160 bpm and considered a
nonreassuring pattern
• Mild = 160 to 180 bpm
• Severe = > 180 bpm
Fetal Tachycardia
• > 200 bpm usually due to fetal
tachyarrhythmia or congenital anomalies
• increased fetal stress when it persists for 10
minutes or longer and with decreased
variability
19
Fetal tachycardia with possible onset of decreased
variability (right) during the second stage of labor.
Fetal heart rate is 170 to 180 bpm. Mild variable
decelerations are present.
Fetal tachycardia due to fetal tachyarrhythmia
associated with congenital anomalies, (in
this case ventricular septal defect). Fetal heart rate is 180
bpm. Notice the "spike" pattern of the fetal heart rate
Fetal Bradycardia
• baseline heart rate < 120 bpm
• 100 to 120 bpm with normal variability - not
associated with fetal acidosis
• < 100 bpm occurs in fetuses with congenital
heart abnormalities or myocardial conduction
defects, such as those occurring in conjunction
with maternal collagen vascular disease.
Fetal Bradycardia
• 80 to 100 bpm - moderate bradycardia & is a
nonreassuring pattern.
• < 80 bpm - severe prolonged bradycardia that
lasts for 3 minutes or longer is an ominous
finding indicating severe hypoxia and is often a
terminal event.
.
Causes of Severe Fetal Bradycardia
Prolonged cord compression
Cord prolapse
Tetanic uterine contractions
Paracervical block
Epidural and spinal anesthesia
Maternal seizures
Rapid descent
Vigorous vaginal examination
Periodic FHR Changes
Accelerations
• transient increases in the FHR usually associated
with fetal movement, vaginal examinations, uterine
contractions, umbilical vein compression, fetal scalp
stimulation or even external acoustic stimulation.
• acceleration pattern preceding or following a
variable deceleration (the "shoulders" of the
deceleration) is seen only when the fetus is not
hypoxic
•
.
FIGURE 1. Reassuring pattern. Baseline fetal heart rate
is 130 to 140 beats per minute (bpm), preserved beat-tobeat and long-term variability. Accelerations last for 15 or
more seconds above baseline and peak at 15 or more
bpm. (Small square=10 seconds; large square=one
minute)
Early Decelerations
•
•
•
•
caused by fetal head compression during uterine
contraction
uniform shape, with a slow onset that coincides
with the start of the contraction and a slow return
to the baseline that coincides with the end of the
contraction
characteristic mirror image of the contraction
Not associated with fetal distress and thus are
reassuring, must be carefully differentiated from
the other, nonreassuring decelerations.
Early deceleration. Notice that the onset and the return
of the deceleration coincide with the start and the end of the
contraction, giving the characteristic mirror image
•
•
Late Decelerations
fetal heart rate beginning at or after the peak of the uterine contraction
and returning gradually and smoothly to baseline only after the
contraction has ended .
associated with uteroplacental insufficiency and provoked by
uterine contractions
 Postdatism, preeclampsia, chronic hypertension and diabetes mellitus
are causes of placental dysfunction.
 Other maternal conditions such as acidosis and hypovolemia
associated with diabetic ketoacidosis lead to decrease uterine blood
flow
late decelerations and decreased baseline variability.
 All late decelerations are considered potentially ominous esp with
decreased beat-to-beat variability
Nonreassuring pattern of late decelerations with
preserved beat-to-beat variability
).
Late deceleration with loss of variability. This is an
ominous pattern, and immediate delivery is indicated.
Variable Decelerations
 caused by compression of the umbilical cord




occludes
the UV, results in an acceleration (shoulder of the
deceleration) followed by occlusion of UA which results in
the sharp downslope.
characteristically variable in duration, intensity and
timing.
resemble the letter "U," "V" or "W" and may not bear a
constant relationship to uterine contractions.
most commonly encountered patterns during labor and
occur frequently in patients with premature rupture of
membranes and decreased amniotic fluid volume.
recovery phase due to the relief of the compression and
the sharp return to the baseline
Variable Decelerations
 classified according to depth and duration as
 Mild - depth above 80 bpm; duration < 30 seconds;
 Moderate- depth between 70 and 80 bpm; duration
between 30 and 60 seconds
 Severe- depth < 70 bpm; duration > 60 seconds.
 generally associated with favorable outcome.
 persistent variable deceleration pattern may lead to
acidosis and fetal distress.
 Nonreassuring variable decelerations with loss of beat-tobeat variability represent an ominous pattern.
Variable deceleration with pre- and postaccelerations ("shoulders").
Severe variable deceleration with overshoot. However,
variability is preserved.
Late deceleration related to bigeminal contractions. Beat-tobeat variability is preserved. Note the prolonged contraction pattern
with elevated uterine tone between the peaks of the contractions,
causing hyperstimulation and uteroplacental insufficiency.
Sinusoidal Pattern
 true sinusoidal pattern is rare but ominous; associated
with high rates of fetal morbidity and mortality.
 characterized by a stable baseline heart rate of 120 - 160
bpm and absent beat-to-beat variability.
 indicates severe fetal anemia, occurs in cases of Rh
disease or severe hypoxia.
 "pseudosinusoidal" pattern - benign, uniform long-term
variability pattern w/less regularity in shape and
amplitude of the variability waves and the presence of
beat-to-beat variability
Pseudosinusoidal pattern
Note the decreased regularity and the preserved beat-to-beat
variability
TRUE SINUSOIDAL PATTERN
Regular, smooth, undulating form , typical of a sine wave that occurs
with a frequency of two to five cycles per minute and an amplitude
range of five to 15 bpm.
THANK