This document discusses fetal heart rate monitoring techniques and patterns. It describes intermittent auscultation using a fetoscope or Doppler ultrasound, and continuous electronic fetal monitoring using cardiotocography. Normal fetal heart rate is between 120-160 bpm; patterns like late decelerations, variable decelerations, or a sinusoidal pattern are non-reassuring. The document outlines how to interpret and manage different fetal heart rate patterns.
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ďą FHR monitoring in real sense is fetal brain monitoring because
fetal brain responds to hypoxia by altering FHR.
ďź Methods of fetal heart rate monitoring styles .
ďź Intermittent auscultation
ď§ Fetoscope.
ď§ Doppler US device.
ďź Continuous electrical FHR monitoring (EFM).
ď§ Cardiotocography (CTG).
FHRMâŚ
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Intermittent auscultation
ďąAdvantages
ďź widely available, easy inexpensive.
ďź Effective if done in consistent manner at appropriate
interval for the stage of labor.
ďąLimitation
ďź Sometimes difficult in obesity & polyhydramnios .
ďź Canât detect early fetal heart beat abnormality.
FHRMâŚ
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Advantages of EFM over clinical monitoring.
ď§ Can detect hypoxia early and can explain the mechanism of
hypoxia and its specific treatment.
ď§ It is an important record for medico legal purpose.
FHRMâŚ
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Drawbacks:
ď§ Due to error of interpretation C/S rate may be high.
ď§ Instruments are expensive and trained personnel are required to
interpret a trace.
ď§ Mother has to be confined in bed.
FHRMâŚ
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Indications for electronic fetal monitoring
ď§ Previous history of stillbirth.
ď§ Induction of Labor.
ď§ Preterm labor.
ď§ Non- reassuring fetal status; decreased fetal movât
ď§ Meconium staining of amniotic fluid.
FHRMâŚ
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Base line rate.
ďź Average fetal heart rate of a ten minutes recording.
ďź Draw a horizontal line by excluding acceleration and deceleration.
ď§ Normal = 120 to 160 bpm
ď§ Bradycardia <120 bpm
ď§ Tachycardia >160 bpm
FHRMâŚ
9. Periodic changesâŚ
Acceleration
ď§ An abrupt increase in the FHR above the baseline. Before 32
weeks of gestation, accelerations should last 10 sec and peak 10
bpm above baseline.
ď§ After of 32 weeks gestation, accelerations should last 15 sec and
peak 15 bpm above baseline.
ď§ A prolonged acceleration is lasting 2 minutes above the base
line but less than 10 minutes.
ď§ An acceleration of 10 minutes or more is considered a change in
baseline.
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Periodic changesâŚ
11. Periodic changesâŚ
ď§ Except those associated with variable deceleration, accelerations are
physiologic response to fetal movement.
ď§ Presence of acceleration âreassuring.
ď§ Absence of acceleration-fetus is not moving (doesnât necessarily mean
hypoxia).
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Periodic changesâŚ
12. Deceleration; Four principal type based on timing, relationships to
contractions, duration and shape.
Early deceleration
ď§ Gradual decrease in FHR and return to base line associated with
a uterine contraction.
ď§ The onset, nadir and recovery of decelerations are coincident
with the beginning , peak and ending of contraction
respectively.
ď§ Caused by compression of fetal head by the uterine cervix (it
stimulates vagal nerve).
ď§ Not associated with fetal hypoxia, acidemia or low APGAR
scores.
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Periodic changesâŚ
13. Late deceleration
ď§ Gradual decrease and return to baseline FHR associated with
uterine contraction.
ď§ The onset of deceleration occur at or after the pick of uterine
contraction and returning to baseline only after the
contraction has ended.
Causes
⢠Excessive Ux contraction (oxytocin).
⢠Feto-placental insufficiency .
⢠Maternal hypotension (epidural ).
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Periodic changesâŚ
14. Variable deceleration
ď§ Abrupt decrease in FHR below the base line, onset, depth and
duration have no relation with contractions.
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17. ⢠Prolonged deceleration
ď§ Decrease in FHR below the baseline âĽ15bpm, lasting âĽ2min
but <10min from the onset to return to baseline.
ď§ May be caused by any of the mechanisms mentioned so far,
but are of a profound and sustained nature.
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Periodic changesâŚ
19. Sinusoid patternâŚ
Criteria for identifying sinusoidal FHR pattern
ď§ A stable baseline FHR of 120-160bpm with regular sine
wave-like oscillations.
ď§ An amplitude of 5-15bpm.
ď§ Oscillation of sine wave above and below the baseline
and absence of accelerations.
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Periodic changesâŚ
21. Interpretation of FHR patterns
ď§ The FHR pattern recorded by an electronic FHR monitor is typically
interpreted as Reassuring FHRP or Non reassuring FHRP.
Reassuring fetal heart rate pattern includes
ď§ A baseline fetal heart rate of 120 to 160 bpm.
ď§ Absence of late or variable FHR decelerations .
ď§ Moderate FHR variability (6 to 25 bpm).
ď§ Early decelerations may or may not be present.
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Periodic changesâŚ
22. Interpretation of FHR patternsâŚ
ďźNonreassuring FHRP
ď§ Replaces the term fetal distress.
ďźNon reassuring FHRP includes
ď§ Late decelerations (>50% of contraction).
ď§ Variable deceleration.
ď§ Sinusoidal tracing
ď§ Prolonged decelerations./recurrent/*
ď§ Bradycardia / tachycardia.
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Periodic changesâŚ