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I. Fetal movements II. Fetal breathing movements III. Contraction stress test IV. Non-stress test V. Biophysical profile VI. Amnionic fluid volume VII.

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Presentation on theme: "I. Fetal movements II. Fetal breathing movements III. Contraction stress test IV. Non-stress test V. Biophysical profile VI. Amnionic fluid volume VII."— Presentation transcript:

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3 I. Fetal movements II. Fetal breathing movements III. Contraction stress test IV. Non-stress test V. Biophysical profile VI. Amnionic fluid volume VII. Umbilical Artery Doppler Velocimetry Current recommendations Significance of fetal testing

4 - In the 1 st William obstetric edition 1903: FHR > 160 b/m or < 100 b/m is dangerous - Now the fetus is considered as a 2 nd patient and exposed to serious morbidity and mortality > his mother - Fetal testing is now extended to the embryonic life: e.g. Embryonic HR may predict pregnancy outcome

5 Our goal is to prevent fetal death Fetal death within 7 days of a normal test is very rare In most tests: +ve predictive value (true +ve) = 99.8% --ve predictive value of abnormal tests (true –ve) = 10 – 40%

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7 - FMs starts at 7 th week - At 8 th week  FMs are never absent > 13 minutes - At 20 – 30 weeks  organization of FMs ( rest - activity cycles) - In the 3 rd trimester until 36 weeks  maturation of FMs - > 36 weeks  behavioral states

8 FHR FMs 1F quite sleep vvvvvv no 2F active sleep VVVVV I 3F VVVVV no 4F awake state VVVVV IIIIII + FHR accelerations The presence of F3 is debate Continuous eye movements are present in: 2F, 3F, 4F

9 At 38 weeks 75% of the time 1F&2F Study: Urinary bladder ↑ in 1F and ↓ in 2F Sleep – awake cycles: Sleep  20 - 75 minutes Mean = 23 minutes Maternal perception of FMs is described as: weak - strong - rolling

10 FMs is α to AFV: As GA ↑ > 20 weeks  weak FMs ↓ vigorous FMs ↑ > 32 weeks strong FMs ↓ due to:  ↓ AFV  ↓ space Normal FMs: = 4 – 10 FMs / 12 hours

11 In 1973  ↓ FM precede fetal death Methods of measuring FMs:  Tocodynamometer  U/S  Maternal perception Study: Maternal perception = 80% of FMs by U/S Study: - > 36 weeks, maternal perception = 16% - Longer FMs > 20 seconds are better felt

12 Optimal number and duration of FMs: Not defined Study: Normal FMs = 10 FMs/2 hours Study: FM/1 hour is good if ≥ previous count Patient complaint of ↓ FMs in the 3 rd T: Not uncommon = 7%  same pregnancy outcome  Evaluate & reassure

13 NST is indicated if:  Abnormal fetal growth by U/S  Abnormal Doppler Study: Mean duration to record 10 FMs = 2.7 hours of counting/day Study: Asking mothers about FMs each visit = counting FMs

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15 In 1972  inward and outward flows of tracheal fluid in sheep = BMs BMs differ from FMs:  Paradoxical = inspiration collapse expiration distend  Not continuous May be coughing to expel AF debris Essential for fetal development

16 Types of BMs:  Gasps/sighs = 1 - 4/minute  Irregular bursts = up to 240c/m As GA ↑  BMs rate ↓ & volume ↑ At 33 – 36 weeks = lung maturation 30 - 40 weeks  diurnal variation:  ↑ after meals  ↓ at night

17 If BMs are not seen  extend U/S evaluation for up to 2 hours before diagnosis of absent BMs Factors affecting BMs: Hypoxia Sound Hypoglycemia Cigarette Labor FHR Impending PTL GA Amniocentesis

18 BMs as a marker of fetal wellbeing: Unfulfilled because multiple factors it affect it, but it is included in BPP with Other indices

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20 Basis: Uterine contractions  ↑ amnionic fluid P  collapse of uterine vessels  isolation of intervillous space  transient ↓ O 2 exchange If uteroplacental pathology is present  late decelerations

21 CST is present since 1972 Late decelerations: Start at/or beyond the acme of uterine contraction Disadvantages: Require 1 ½ hours

22 Method: Oxytocin 0.5 mIU/minute by infusion pump doubled /20 minutes  3 contractions in 10 minutes duration of each ≥ 40 seconds Nipple stimulation: 1 nipple is rubbed through her clothes for 2 minutes or until contractions start, restart After 5 minutes  3 contractions in 10 min Advantages: ↓ time and cost May  hyperstimulation with mild FD

23 Negative: No LD or significant VD Positive: LD + 50% of contractions even if contractions are < 10/m Equivocal-suspicious:  Intermittent LD  Significant VD Equivocal-hyperactive:  LD + > 3 contractions/10m  Contraction > 90 seconds Unsatisfactory:  < 3 contractions /10m  Uninterruptable tracing

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25 1975 Basis: FMs  FHR accelerations = good sign Equipments:  Doppler  Maternal perception of FMs Differ from CST and much easier Used to discriminate false +ve CST Used in BPP

26 Physiology: Beat to beat variability > 5 b/m + FHR accelerations = good autonomic function Most common causes of no accelerations:  Fetal sleep  Drugs As GA ↑  ↑ FMs + ↑ FHR accelerations 25 – 28 weeks accelerations are  70% 15 b/m for 15 seconds 90% 10 b/m for 10 seconds < 32 weeks use 10 b/m for 10 seconds

27 Normal NST: Vary in number, amplitude & duration of acceleration = ≥ 2 accelerations that peak at ≥ 15 b/m for ≥ 15 seconds in 20 minutes ± FM 1 acceleration is enough by some If no accelerations  extend examination to 40-75-80-120 minutes before diagnosis of nonreactive NST

28 No accelerations = not bad fetus False +ve NST ≥ 90% Disadvantages of NST:  ↑cost  Irreducibility Computerized analysis:  ↓ cost  Reliable  objective

29 Abnormal NST: - Silent oscillatory pattern = ominous = beat - to - beat variability < 5 b/m + no accelerations - Terminal cardiogram: Both + LD = uteroplacental insufficiency

30 Abnormal NST is associated with: FGR 75% Oligohydramnios 80% Acidosis 40% Meconium 30% Placental infarction 93% Study: Nonreactive NST for ≥ 90 min is associated with ↑ perinatal pathology in 93%

31 Interval between tests: 1/week 2/week, 1/day, > 1/day in:  Postterm  Type 1 DM  FGR  PIH

32 Decelerations: Normally present in ½ to 2/3 of fetuses Variable decelerations: Not ominous if nonrepetitive and brief < 30 seconds Repetitive VD ≥ 3 /20 minutes even if mild are associated with ↑ CS for FD Decelerations ≥ 1 min  bad prognosis

33 Study: - Addition of NST to AFV  75% CS for FD in cases of ↑ VD + ↓ AFV - FD in labor + normal AFV is increased in patients with VD False - normal NSTs: = fetal death within 7 days of a normal NST

34 Mean interval between testing and death: = 4 days Range: = 1 - 7 days Most common indication of NST: = postterm Most common autopsy findings:  Meconium  Abnormal umbilical cord

35 = Acute asphyxial insult = NST is inadequate to preclude such an acute asphyxial events Other causes:  Fetomaternal Hg  Infection  Abruptoplacenta  Congenital anomalies  Abnormal cord insertion

36 Acoustic Stimulation Tests: Artificial larynx  acoustic stimulation to ↑ acceleration Method: External sound for 1 – 2 seconds Repeat 1 – 3 times for up to 3 seconds Still under evaluation

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38 Manning & colleagues 1980 5 variables to ↓ false +ve ↓ false –ve results Equipments:  Doppler  Real time U/S Duration of testing: 1/2 – 1 hour

39 2 0 NST ≥ 2 accelerations < 2 (≥15 b/m for ≥15 sec in 40 minutes) FBMs ≥ 1 ≥ 30 sec in 30 m < 30 sec FMs ≥ 3 in 30m < 3 F Tone ≥ 1 -- AFV > 2 cm ≤ 2 cm ( largest single vertical pocket)

40 Fetal tone = flexion and extension of one limb or opening or closing hand NST is not required if the 4 variables are normal AFI if the largest vertical pocket is ≤ 2 cm  should be evaluated BPP = 6 is equivocal and poor predictor of abnormal outcome BPP = < 6 is progressively more accurate predictor of abnormal outcome

41 Study: BPP followed by cordocentesis for pH: - 20% of fetuses are FGR - 80% of fetuses have alloimmune hemolytic anemia BPP = 0 is associated with acidemia BPP = 8 - 10 is associated with normal pH

42 Study: BPP+cordiocentasis in DM  no benefit Study: BPP+cordiocentasis in GR  no benefit The morbidity and mortality in GR depend on GA & wt not BPP results Modified BPP( abbreviated BPP 1989): = vibroacoustic NST + AFV X 2/week Duration of testing = 10 minutes

43 If AFV is < 5 do complete BPP or CST CST  ↑CS for false abnormal results Acceptable by ACOG False –ve rate = 0.8 : 1000 False +ve rate = 1.5 : 1000 Study: Excellent method with no unexpected FD

44 BPP = 10:  Repeat 1/w 2/w in DM & postterm BPP = 8 -10 + normal AFV:  Repeat BPP = 8 -10 + ↓ AFV: Chronic fetal asphyxia suspected  Deliver

45 BPP = 6: Possible fetal asphyxia If > 36 weeks + normal AFV + favorable cervix  deliver If < 36 weeks + normal AFV  repeat: if ≤ 6  deliver if > 6  repeat If + ↓ AFV  deliver

46 BPP = 4: Probable fetal asphyxia  repeat same day if ≤ 6  deliver BPP = 0 - 2: Almost certain fetal asphyxia  deliver

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48 Basis: Uteroplacental insufficiency  ↓ fetal renal blood flow  ↓ urine production  ↓ AFV Methods:  AVI  Largest vertical pocket  2 x 2 cm pocket

49 Study: AFI < 5 cm  ↑ CS for FD ↑ low 5 minutes Apgar score ↑ perinatal morbidity & mortality Study: 20% of fetuses have AFI < 5 cm AFI = poor diagnostic test Study: Same results in severe preeclampsia

50 Study: Nonintervention to permit spontaneous VD in fetuses with AFI < 5  same pregnancy outcome as induction of labor

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52 Basis: To assess blood flow by characterizing downstream impedance Uterine artery S/D ratio: Most commonly useded, abnormal if: - ↑ 95 th percentile for GA - Diastolic flow is: Absent (perinatal mortality = 10%) Reversed (perinatal mortality = 33%)

53 Both absent and reversed diastolic flow are associated with IUGR Study: NST = Doppler Study: No benefit other than suggesting GR Study: No benefit in other diseases as: PIH, DM, lupus anticoagulant, postterm

54 Middle cerebral artery S/D ratio: May reflect fetal compromise Based on brain sparing theory: = uteroplacental insufficiency  ↑ blood flow + ↓ impedance Study: No significant difference Still under evaluation

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56 No agreement for the best test All tests have different end points that are considered according to the clinical situation When to start? Most important considerations in deciding when to start:  Prognosis of neonatal survival  Severity of maternal disease In high risk patients at 32 – 34 weeks In more severe cases at 26 – 28 weeks

57 Frequency of testing: ≥ 1/week In parkland hospital: All high risk patients are admitted NST 2 – 3/week for admitted cases If FHR accelerations + Deceleration  No need for delivery If ↓ FMs or ↓ AFV in 3 rd T  Admission in labor suit

58 According to results of NST the patient is:  Discharged  Transformed to high risk ward  Delivered Fetal deaths in high risk patients are low Most fetal deaths are in low risk patients due to unpreventable events as:  Placental abruptions  Cord accidents

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60 Does it make any difference? Fetal surveillance in 1970s = < 1% in 1980s = 15% Fetal death rate ↓ in high risk tested patients # untested patients Study: NSTs/CSTs are not recommended because of ↑ cost

61 Study: No benefit of testing  forms of care likely to be ineffective or harmful Can we identify fetal asphyxia early enough to prevent brain damage? Study: Abnormal NST is associated with ↓ cognition # Doppler = by the time fetal compromise is diagnosed, brain damage is already sustained

62 Study: CP in high risk patients managed by BPP = 1.3 : 1000 live birth # 4.7 : 1000 in controls In a prior report: CP is associated with ↓ BPP scores = identification is too late

63 In the last 2 decades: - Methods are continuously evolving = dissatisfaction - Wide range of normal variables: How many accelerations–FMs–FBMs duration and frequency of testing - Abnormal results are seldom reliable = forecast fetal wellness rather than illness


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