Cardiotocography ( CTG )Electronic Fetal Monitoring Ali Sungkar Divisi Fetomaternal Bagian Obstetri dan Ginekologi FKUI/RSUPN - CM
Electronic Monitoring • Indirect (external monitoring)
EFM-ISSUES • Detect fetal hypoxia i.e reduce and avoid harm to the fetus and improve fetal and baby out-come. • Severe acidosis may result in FHR changes. • Could occur in Normal physiological response in labor. • Misunderstanding the physiological and pathphysiological CTGs will improve the Mx.
EFM Problems and Realities • Electronic Intra-partum FHR Monitoring is now considered mandatory for high-risk pregnancies. • Difficulties with interpretation include over confidence and not-only difference in opinion between practitioners but, also when the same practitioner examines the same CTG twice. • Increases CS rates 1.41%rr.
EFM Problems and Realities • Increases operative vaginal delivery 1.20%rr. • And no change in incidence of C Palsy. • Reduction in Neonatal seizures rates 0.51% • No difference in APGAR scores. • ? About the efficacy.
EFM- Facts • Reliability of interpretation-50-75% are false positive . • False positive Dx reduces to 105 with FBS. • FBS 93% sensitivity, 6% false positive. • PH Vs Lactate -39% Vs 2.3(rr 16.7).
Indications for the continuous EFM High risk pregnancies IOL and Augmentation of Labour. Reduced FM. Premature labour/TPL. APH/IPH Oligohydramnios Hypertension. Abnormal FHR detected. Malpresentation and in labour. DM,Multiple Gestation. Previous CS. Abdominal Trauma. Prolonged ROM. Meconium Liq. Electronic Fetal Monitoring-Indications
EFM- Interpretation Consider : • Intrapartum/antepartum trace. • Stage of labour. • Gestation. • Fetal presentation, ? Malpresentation. • Any augmentation,? IOL Medications • Direct or indirect monitoring/
EFM-4 Basic Features. • Baseline FHR - Mean level of FHR when this is stable, excluding Accelerations and Decelerations (110-160 bpm) -Tachycardia -Bradycardia • Baseline Variability-5 bpm or greater than or equal to 5bpm, between contractions -Normal -Non-reassuring-Less than 5 bpm or less but less than 30 min -Abnormal-less than 5 bpm for 90 min or more.
FHR: Variability • Definitions • Short term • Long term
Baseline variability • The minor fluctuations on baseline FHR at 3-5 cycles p/m produces Baseline variability. • Examine imin segment and estimate highest peak and lowest trough. • Normal is more than or equal to 5 bpm.
Factors affecting Baseline variability. • Para-Sympathetic affects short term variability whilst Long Term is more Symp. • CNS ,Drugs reduce Variability • High gestation increases variability • Mild Hypoxia may cause both S and para S stimulation.
Non-reassuring Baseline variability. • NRCTGs- reduced or less than 5 bpm for 40 min or more but less than 90 mins.. • B-B or short Term V is varying intervals between successive heart beats . • Long Term v is irregular waves on the CTG 3-5 bpm. • Normal is 5-25 bpm– this indicates N-CNS.
EFM-Accelerations • Accelerations- transient increase in FHR of 15 bpm or more lasting for 15 sec. • Absence of accelerations on an otherwise normal CTG remains unclear. • Presence of FHR Accelerations have Good outcome.
EFM Decelerations • Decelerations- transient slowing of FHR below the baseline level of more than 15 bpm and lasting for 15 sec. or more.
Electronic Fetal Monitoring • a) Early Decelerations (fig 3) • Head compression • Begins on the onset of contraction and returns to baseline as the contraction ends. • Should not be disregarded if they appear early in labor or Antenatal. • Clinical situation should be r/v
Late Decelerations. • Uniform periodic slowing of FHR with the on set of the contractions . • Repetitive late decels increases risk of Umbilical artery acidosis and Apgar score of less than 7 at 5 mins and Increased risk of CP.
Electronic Fetal Monitoring b) Late Decelerations (Fig 4) • Due to acute and chronic feto-placental vascular insufficiency • Occurs after the peak and past the length of uterine contraction, often with slow return to the baseline. • Are precipitated by hypoxemia • Associated with respiratory and metabolic acidosis • Common in patients with PIH, DM, IUGR or other form of placental insufficiency.
Late Decelerations • Reduces Baseline variability together with Late Decelerations or Variable Decelerations is associated with increased risk of CP.
EFM- Variable Decelerations • Variable intermittent periodic slowing of FHR with rapid onset recovery and isolation. • They can resemble other types of deceleration in timing and shape. • Atypical VD are associated with an increased risk of umbilical artery acidosis and Apgar score less than 7 at 5 min
EFM- Variable Decelerations Additional components: • Loss of 1 degree or 2 degree rise in baseline Rate • Slow return to baseline FHR after and end of contraction. • Prolonged secondary rise in Base FHR • Biphasic deceleration • Loss of variability during deceleration • Continuation of base line at a lower level.
Electronic Fetal Monitoring c) Variable Deceleration (Vagal activity) (Fig 5) • Inconsistent in configuration, • No uniform temporal r-ship to the onset of contraction, are variable and occur in isolation. • Worrisome when Rule of 60 is exceeded (i.e. decrease of 60 bpm,or rate of 60 bpm and longer than 60 sec) • Caused by cord compression of the umbilical cord • Often associated with Oligo-hydroaminos with or without ROM • Can cause short lived RDS if they MILD • Acidosis if prolonged and Recurrent.
EFM Prolonged deceleration Prolonged Deceleration (Fig 6) • Drop in FHR of 30 bpm or More lasting for at least 2 min • Is pathological when crosses 2 contractions i.e 3 mins. • Reduction in O2 transfer to placenta. • Associated with poor neonatal outcome.
EFM- Prolonged DecelerationsCAUSES • Cord prolapse. • Maternal hypertension • Uterine Hypertonia • Followed by a VE or ARM or SROM with High PP.
EFM Mx Prolonged Deceleration • Maternal position • IV fluids • V.E to exclude cord prolapse • Assess BP • FBS if cx dilated and well applied PP • Mx Dependingon the clinical situation.
Baseline Bradycardia • FH below 110bpm(FIGO ). • less than 100bpm (RANZCOG). Causes : • Postdates, Drugs, Idiopathic, • Arrythmias, hypothermia(increased Vagal Tone) • Cord Compression (Acute Hypoxia, congenital H/disease and Drugs). • Mx depends on the clinical situation.(FBS,VE Observation or expedite delivery)
Types • Moderate Bradycardia 100-109 bpm • Abnormal bradycardia less than 100bpm. • Tachycardia 161-180 bpm • Abnormal Tachycardia more than 180 bpm • Ranzcog Australian more than 170 bpm
Baseline tachycardia and Bradycardia. • Uncomplicated baseline tachycardia 161-180 bpm or bradycardia 101-109 do not appear to be associated with poor NN outcome.
Causes of B Tachycardia. • Asphyxia • Drugs • Prematurity • Maternal Fever • Maternal thyrotoxicosis • Maternal Anxiety • Idiopathy • Mx depends on the clinical situation
Electronic Fetal Monitoring Baseline Bradycardia • FH Rate below 110bpm (FIGO Recommended) • Postdates • Drugs • Idiopathic • Arrhythmia's • Hypothermia.(Increased Vagal tone), • Cord compression(Acute Hypoxia,Congenital H/disease, and drugs) Mx depends on the clinical situation. (FBS, VE, Observation or expedite Delivery).
Electronic Fetal Monitoring Baseline Tachycardia • Asphyxia • Drugs • Prematurity • Maternal fever • Maternal thyrotoxicosis • Maternal Anxiety • Idiopathy Mx depends on the clinical situation
EFM-Sinusoidal Pattern • Regular Oscillation of the Baseline long-term Variability resembling a Sine wave ,with no B-b Variability (Fig 2), • Has fixed cycle of 3-5 p min. with amplitude of 5-15 bpm and above but not below the baseline. • Should be viewed with suspicion as poor outcome has been seen (eg Feto-maternal haemorrhage)
Electronic Fetal Monitoring Sinusoidal pattern - distinctive smooth undulating Sine-wave baseline with no B-b variability ( Fig 2 ) • 0.3 % (Young 1980) • cord compression • hypovolemia • ascites • idiopathic(fetal thumb sucking) • Analgesics • Anaemia • Abruption • Mx r/v clinical situation
EFM- Saltatory pattern • Seen During Fetal thumb sucking. • Could be associated with Hypoxia.
NR CTGs • Difficult to interpretation,leads to Increased rate of C Section. • 50% CTG in Labour have 1 abnormal feature • 15-20% Nr CTGs (pathological). • ?? To reduce CS….
EFM-Summary • Normal - CTG with all 4 Features • Suspicious -one non reassuring category and reminder are reassuring • Pathological -2 or more non-reassuring categories or one or more abnormal categories.