Antepartum Fetal Surveillance: Aboubakr Elnashar

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Antepartum fetal surveillance

Transcript of Antepartum Fetal Surveillance: Aboubakr Elnashar

  • Aboubakr Elnashar
  • Aboubakr Elnashar
  • Fetal Neurodevelopment Function Center Week Tone cortex/subcortex 7.5-8.5 Movement cortex/nucle 9 Breathing i ventral surface of fourth ventricle 20-21 Fetal heart rate reactivity posterior hypothalamus/ medulla 24 Aboubakr Elnashar
  • Patterns of foetal activity 1.Fetal breathing movements 2.Gross body movements 3.Fine motor movements Aboubakr Elnashar
  • Fetal behavioral states (Nijhuis et al, 1982): F1: quiescent state (quiet sleep) F2: Frequent gross body movements F3: Continuous eye movement. This state was disputed (Philia & James, 1990) F4: Vigorous body movements & FHR accelerations Aboubakr Elnashar
  • During the last 10 w of pregnancy: F. breathing movements: 30% of the time Gross body movements: 10% of the time At term: Cycling between activity & quiescence occurs over a time span of 60 min Activity is highest in late evening FHR variation increases during fetal activity Accelerations are associated with f. body movements. Aboubakr Elnashar
  • Adaptations to hypoxia Early 1.Reduced FHR reactivity 2.Absence of breathing movements Late: 1. Reduced body movements and tone 2. Reduced liquor (renal hypoperfusion) Aboubakr Elnashar
  • Aboubakr Elnashar
  • The ideal test 1. Quick 2. Easy to perform 3. Interpreted results that are reproducible. 4. Clearly identify the compromised fetus at a stage at which intervention will improve the outcome 5. Not give an abnormal result for a healthy fetus. Unfortunately, this ideal test does not yet exist! Aboubakr Elnashar
  • I. Fetal movements counting (FMC) II. Fetal heart rate recording 1.CTG 2.Non-Stress Test (NST) 3.Contraction StressTest (CST) or Oxytocin Challenge Test (OCT) 4.Nipple stimulation test 5.Vibroacoustic stimulation (VAS) 6.Computerized CTG III. Biophysical Profile (BPP) IV. Doppler Aboubakr Elnashar
  • I. Fetal movements counting (FMC) Idea: Sadovsky and Yaffee (1973) pre-eclamptic patients noticed decreased fetal movement prior to fetal demise. Aboubakr Elnashar
  • Women perceive most movement when lying down fewer when sitting and least while standing. Busy pregnant women: not concentrating on fetal activity: often report a misperception of RFM. Aboubakr Elnashar
  • important clinical sign: significant reduction or sudden change in movement The fetus may be in a state of sleep or the mother may be too busy to focus on fetal activity. Although fetal movements tend to plateau at 32 w, there is no reduction in the frequency of fetal movements in the late 3rd trimester. Aboubakr Elnashar
  • How to perform?. 1.One to Two Hours Method. The patient is asked to relax on her left side 30 min after eating. The patient should record the time that she starts the test and note each time the baby kicks. Normal: 3-5 Kicks within 60 min Normal: 10 within 60-75 minutes. Aboubakr Elnashar
  • Aboubakr Elnashar
  • 2. The Cardiff Count-to-Ten chart: The patient records fetal movements during the course of usual daily activity. warning signal: 12 hours without at least 10 perceived movements: patient should be evaluated and should undergo further testing e.g. NST. Aboubakr Elnashar
  • Advantages: 1. Inexpensive & noninvasive 2. An effective screening measure {reductions in fetal mortality from 8.7 deaths per 1,000 live births to 2.1 deaths per 1,000 live births}. Some authorities suggest that all pregnant patients, regardless of risk factors, be counseled about formal assessment of fetal movement. Aboubakr Elnashar
  • Disadvantages: 1. US studies: mother can feel up to 80% of movements seen on scan after 36 w, a mother may feel only 15% of movements. 2. No defined number of movements that must be felt, nor is it known over what time frame the testing should occur. Aboubakr Elnashar
  • 3. Routine daily FMC followed by appropriate action when movements are reduced offer no advantage over informal inquiry about movements during standard antenatal care & selective use of formal counting in high risk cases{B} (RCT of 68000 women). 4. Although the study did not rule out a beneficial effect of FMC, the policy would have to be used by 1250 women to prevent one perinatal death. Aboubakr Elnashar
  • Should fetal movements be counted routinely in a formal manner? insufficient evidence to recommend formal fetal movement counting using specified alarm limits (NICE) Women should be advised to be aware of their babys individual pattern of movements. If they are concerned about a reduction in or cessation of fetal movements after 28+0w, they should contact their doctor. and should not wait until the next day for assessment of fetal wellbeing. Aboubakr Elnashar
  • The effect of FMC in high-risk pregnancies is not known Prudent pay careful attention to their fetal movements. reduction or an alteration in the movements of their fetus should be offered some form of assessment of fetal well-being [E]. Aboubakr Elnashar
  • II. Fetal heart rate recording 1.CTG 2.NST 3.Contraction stress test 4.Nipple stimulation test 5.Acoustic stimulation test 6.Computerized CTG Aboubakr Elnashar
  • 1. Fetal heart rate tracings (CTG) METHOD Simultaneous recordings are performed by two separate transducers, one for FHR and second one for UC Aboubakr Elnashar
  • INTERPRETATION 1.Normal/Reassuring Trace Baseline FHR: 110-150 b/m Baseline variability: 10-25 b/m At least 2 accelerations (>15 beats for> 15 sec in 20 min) No decelerations. Aboubakr Elnashar
  • 2. Suspicious/Equivocal Trace. Baseline FHR: 150-170 b/m or 100-110 b/m Reduced baseline variability (5-10 b/m for >40 m) Absence of accelerations for >40 m Sporadic deceleration of any type. absence of accelerations diminished variability late decelerations with weak spontaneous contractions. Aboubakr Elnashar
  • Aboubakr Elnashar
  • Abnormal/Pathological Trace - Baseline FHR: 170 b/m Silent Pattern (40 min Sinusoidal pattern (oscillation frequency = 2-5 cycles/min, amplitude of 5-15 b/m) for >40 m No accelerations No area of normal baseline variability Repeated late, prolonged (> 1 minute) severe variable* (>40 b/m) decelerations. *decelerations vary in depth, vary in duration and vary in timing relative to the uterine activity Aboubakr Elnashar
  • Tachycardia Sinusoidal pattern Late deceleration normal baseline rate at 120 bpm, absent baseline variability, no accelerations late decelerations Aboubakr Elnashar
  • variable fetal heart rate decelerations. Reassuring shoulders (accelerations) are obvious before and after each deceleration. baseline tachycardia minimal variability. Aboubakr Elnashar
  • MANAGEMENT: Normal/Reassuring Trace repeat and/or estimate AFI if considered necessary acc to the clinical situation and indication for testing. Suspicious/Equivocal Trace Continue for up to 60 min {determine the presence of fetal rest/activity cycles}. Further evaluation acc to the cl situation e.g. fetal acoustic stimulation, AFI, BPP, Doppler blood velocity waveform. Abnormal/Pathological Trace deliver if clinically appropriate. Further evaluation/monitoring if not appropriate to deliver. Aboubakr Elnashar
  • Advantages: It is the most commonly performed antenatal test for fetal wellbeing. Quick Simple to perform Aboubakr Elnashar
  • 2. The Non-Stress Test (NST) (Hammacher et al, 1960) Idea: FHR accelerations: linked closely with fetal movements {increased sympathetic output}. The long term variability: {balance between sympathetic & parasympathetic tone} The short term variability (baseline or bandwidth variability) {parasympathetic tone}. Aboubakr Elnashar
  • Steps: 1. left lateral recumbent position. 2. Place and adjust the external tocodynamometer and US transducer to obtain the best possible tracing. 3. Instruct the patient to record f movements on the monitor tracing using the event marker. 4. Observe the EFM tracing until t