Intrapartum Fetal Intrapartum Fetal MonitoringMonitoring

Prof. Ron GonenProf. Ron Gonen

Why Monitor?Why Monitor?

Goals of Fetal MonitoringGoals of Fetal Monitoring

Causes of reduced OCauses of reduced O22 supply to the fetussupply to the fetus

Monitoring MethodsMonitoring Methods

Electronic MonitoringElectronic Monitoring Indirect (external Indirect (external

monitoring)monitoring) TechniqueTechnique AdvantagesAdvantages DisadvantagesDisadvantages

Direct (internal)Direct (internal)

TechniqueTechnique AdvantagesAdvantages DisadvantagesDisadvantages

Basic FeaturesBasic Features Baseline Baseline VariabilityVariability Periodic changes: FHR Periodic changes: FHR

accelerations or decelerations accelerations or decelerations that occur with contractions. that occur with contractions.

Non periodic changesNon periodic changes

Basic Features of Fetal Basic Features of Fetal Heart tracingHeart tracing

Standard guidelines: Baseline Standard guidelines: Baseline RateRate

Normal 120-160Normal 120-160Fetal tachycardiaFetal tachycardiaModMod 161-180161-180Marked Marked 181-more181-moreFetal BradycardiaFetal BradycardiaModMod 100-119100-119Marked Marked 90 or less90 or less

Baseline TachycardiaBaseline Tachycardia

Causes of baseline Causes of baseline tachycardiatachycardia

Chronic / moderate asphyxiaChronic / moderate asphyxia DrugsDrugs PrematurityPrematurity Maternal feverMaternal fever Maternal thyrotoxicosisMaternal thyrotoxicosis Maternal AnxietyMaternal Anxiety IdiopathyIdiopathy

Causes of baseline Causes of baseline bradycardiabradycardia

Severe / prolonged Severe / prolonged asphyxiaasphyxia

DrugsDrugs Fetal cardiac arrhythmiaFetal cardiac arrhythmia IdiopathyIdiopathy

Baseline variabilityBaseline variability

The minor fluctuations on baseline The minor fluctuations on baseline FHR at 3-5 cycles p/m will reflect FHR at 3-5 cycles p/m will reflect baseline variabilitybaseline variability

Examine 1 min segment and estimate Examine 1 min segment and estimate highest peak and lowest troughhighest peak and lowest trough

Normal is more than or equal to 5 bpmNormal is more than or equal to 5 bpm

VariabilityVariability

VariabilityVariability

Factors affecting Baseline Factors affecting Baseline variabilityvariability

Fetal hypoxiaFetal hypoxia Fetal sleepFetal sleep PrematurityPrematurity Drugs reduces VariabilityDrugs reduces Variability

Periodic changesPeriodic changes

DecelerationsDecelerationsEarlyEarlyLateLateVariableVariable

Head compressionHead compression

Begins on the onset of contraction Begins on the onset of contraction and returns to baseline as the and returns to baseline as the contraction ends (vagal stimulation)contraction ends (vagal stimulation)

Early DecelerationsEarly Decelerations

EARLY DECELERATIONEARLY DECELERATION

Early Decelerations

Late DecelerationsLate Decelerations Uniform periodic slowing of FHR Uniform periodic slowing of FHR

with the on set of the contractionwith the on set of the contraction

Reduced baseline variability Reduced baseline variability together with late decelerations together with late decelerations and repetitive late deceleration and repetitive late deceleration increases risk of fetal acidosis and increases risk of fetal acidosis and an Apgar score of less than 7 atan Apgar score of less than 7 at

5/min with an increased risk of 5/min with an increased risk of adverse outcomeadverse outcome

Late Decelerations Due to acute and chronic utero-placental Due to acute and chronic utero-placental

insufficiencyinsufficiency

Occurs after the peak and past the length of Occurs after the peak and past the length of uterine contraction, often with slow return to uterine contraction, often with slow return to the baselinethe baseline

Is precipitated by hypoxemiaIs precipitated by hypoxemia

Associated with respiratory and metabolic Associated with respiratory and metabolic acidosisacidosis

Common in patients with PIH, DM, IUGR or Common in patients with PIH, DM, IUGR or other forms of placental insufficiencyother forms of placental insufficiency

Late DecelerationLate Deceleration

Late DecelerationLate Deceleration

Variable DecelerationsVariable Decelerations Variable intermittent periodic Variable intermittent periodic

slowing of FHR with rapid onset slowing of FHR with rapid onset recoveryrecovery

Inconsistent in configurationInconsistent in configuration No uniform temporal r-ship to the No uniform temporal r-ship to the

onset of contraction, are variable onset of contraction, are variable and occur in isolationand occur in isolation

They can resemble other types of They can resemble other types of deceleration in timing and shapedeceleration in timing and shape

Variable DecelerationsVariable Decelerations Caused by compression of the Caused by compression of the

umbilical cordumbilical cord

Often associated with Oligo-Often associated with Oligo-hydramnios with or without hydramnios with or without rupture of membranesrupture of membranes

Acidosis if prolonged and Acidosis if prolonged and recurrentrecurrent

Severe variable Severe variable decelerationdeceleration

= when Rule of 60 is exceeded (i.e. decrease = when Rule of 60 is exceeded (i.e. decrease of 60 bpm,or rate of 60 bpm and longer of 60 bpm,or rate of 60 bpm and longer than 60 sec) than 60 sec)

Other worrisome featuresOther worrisome features Slow return to baseline FHR after and end of Slow return to baseline FHR after and end of

contractioncontraction Prolonged secondary rise in Base FHRProlonged secondary rise in Base FHR Loss of variability during deceleration Loss of variability during deceleration Continuation of the baseline at a lower rateContinuation of the baseline at a lower rate

Variable DecelerationsVariable Decelerations

Variable Decelerations

Non-periodic changesNon-periodic changes

can occur spontaneously, can occur spontaneously, without contraction activitywithout contraction activity

DecelerationsDecelerations

AccelerationsAccelerations

Non periodic changes:Non periodic changes: Prolonged Deceleration

= = Drop in FHR of 30 Drop in FHR of 30 bpm or more lasting bpm or more lasting for at least 2 minsfor at least 2 mins

Results in reduced of O2 transfer to Results in reduced of O2 transfer to placentaplacenta

May be associated with poor May be associated with poor neonatal outcomeneonatal outcome

Prolonged Deceleration

Prolonged DecelerationsProlonged DecelerationsCAUSESCAUSES

Cord prolapseCord prolapse AbruptionAbruption Maternal hypotensionMaternal hypotension Uterine hypertoniaUterine hypertonia Epidural/spinal or pudendal Epidural/spinal or pudendal

anesthesiaanesthesia

AccelerationsAccelerations Accelerations transient increase in FHR Accelerations transient increase in FHR

of 15 bpm or more lasting for 15 secof 15 bpm or more lasting for 15 sec

Absence of accelerations on an Absence of accelerations on an otherwise normal Fetal heart tracing otherwise normal Fetal heart tracing remains unclearremains unclear

Presence of FHR Accelerations usually Presence of FHR Accelerations usually have good outcomehave good outcome

AccelerationsAccelerations

Intrauterine ResuscitationIntrauterine Resuscitation

Have the mother lie on her left/right Have the mother lie on her left/right sideside

Consider amnioinfusionConsider amnioinfusion Stop any oxytocinStop any oxytocin Increase IV fluidIncrease IV fluid Initiate tocolysisInitiate tocolysis Give oxygen @ 10-12 L/min via maskGive oxygen @ 10-12 L/min via mask

If the FHR is not restored to normal If the FHR is not restored to normal within 30 minutes, prompt delivery is within 30 minutes, prompt delivery is needed. needed. 

      

Sinusoidal PatternSinusoidal Pattern

Regular Oscillation of the Regular Oscillation of the Baseline long-term Variability Baseline long-term Variability resembling a Sine wave fixed resembling a Sine wave fixed cycle of 3-5 p min with amplitude cycle of 3-5 p min with amplitude of 5-15bpm and above but not of 5-15bpm and above but not below the baselinebelow the baseline

Should be viewed with suspicion Should be viewed with suspicion as poor outcome has occurred as poor outcome has occurred (maternal/fetal hemorrhage)(maternal/fetal hemorrhage)

Sinusoidal PatternSinusoidal Pattern

HypovolemiaHypovolemia AscitesAscites Idiopathic (fetal Idiopathic (fetal

thumb sucking)thumb sucking) AnalgesicsAnalgesics AnemiaAnemia AbruptionAbruption

Summary of tracingSummary of tracing Normal with all 4 FeaturesNormal with all 4 Features

BaselineBaseline VariabilityVariability Periodic changesPeriodic changes Non periodic changesNon periodic changes

Suspicious one non reassuring Suspicious one non reassuring category and remainder are category and remainder are reassuringreassuring

Pathological 2 or more non-Pathological 2 or more non-reassuring categories or one or more reassuring categories or one or more abnormal categories.abnormal categories.

Scalp pH samplingScalp pH sampling

Intrapartum Oxygen Intrapartum Oxygen Saturation MonitoringSaturation Monitoring

PurposePurpose

ProcedureProcedure

MiscellaneousMiscellaneous

With all of the With all of the technologytechnology

Caring for the Mom, Caring for the Mom, Not the Monitor!Not the Monitor!

Thank you for your Thank you for your attentionattention