BIOPHYSICAL PROFILE FLAME LECTURE: 56 STELLER 7.2.14.
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Transcript of BIOPHYSICAL PROFILE FLAME LECTURE: 56 STELLER 7.2.14.
BIOPHYSICAL PROFILEFLAME LECTURE: 56
STELLER 7.2.14
Learning Objectives
To understand rationale for fetal assessment To describe approaches for assessment of fetal well being Prerequisite:
FLAME LECTURE 54: Outpatient Antenatal Testing See also – for closely related topics
FLAME LECTURE 53: Overview of Interpreting Fetal Heart Rate Tracings
FLAME LECTURE 54B: The Nonstress Test (NST) and Contraction Stress Test (CST)
FLAME LECTURE 57: Assessment of fetal movement FLAME LECTURE 59: Assessment of amniotic fluid volume
Rationale of Prenatal Outpatient Fetal Assessment
GoalsDetect uteroplacental insufficiencyPrevent stillbirthAvoid unnecessary iatrogenic preterm delivery
Physiologic basis -- The fetal brain is incredibly sensitive to changes in O2 and pH:Under stress, fetal movements decrease as the
fetus attempts to conserve energy1-2
Hypoxia/acidemia Neurologic depression1. Olesen AG. Acta Obstet Gynecol Scand. 20042. Manning FA. AJOG 1993
Antepartum Fetal Distress Cascade
HYPOXIA
ACIDOSIS
LATE DECELERATIONS APPEAR(CST)
ACCELERATIONS DISAPPEAR(NST)
BREATHING STOPS(BPP)
MOVEMENT CEASES(BPP, FMC)
FETAL TONE ABSENT(BPP)
3. Porto M. Clin Ob Gyn. 1987
FETAL CNS CONTROLTONE (7 weeks)
Cortical & subcortical areas
MOVEMENT (9weeks)Cortical Nuclei
BREATHING (20 weeks)Ventral surface 4th ventricle
REACTIVITY (26-28weeks)Posterior Hypothalamus
Looking at variables derived from CNS centers is ideal Tone
Body movements Breathing movements Cardiac activity Eye movements Swallowing Micturition
HYPOXIA
MATURITY
Biophysical Profile (BPP)
Combines the NST, AFI and assessments of fetal breathing, body and limb movements in an exam that lasts up to 30 minutes
BPP score is linearly correlated with fetal pH4
The risk of fetal death within one week of a normal BPP is estimated to be 1/13005
Is initiated ~24-32 weeks qweekly/biweekly False neg rate: .07-.08%, False pos rate: 40-50%6-
84. Manning FA. Am J Obstet Gynec 19935. Manning FA. Am J Obstet Gynec 19876. Mangesi L. Cochrane Database Syst Rev 20077. Freeman RK. Am J Obstet Gynecol 19828. Baschat AA. Ultrasound Obstet Gynecol. 2006
Rationale of Including Assessment of Amniotic Fluid Volume in the BPP In fetal hypoxia, fetal autoregulation of vascular tone
preserves essential organsBlood flow is directed to the brain, heart and adrenals
and away from the kidneys Over time: a decrease in renal perfusion a decrease in
fetal urine production oligohydramniosTherefore low AVF is a marker of CHRONIC uteroplacental
insufficiency The other, CNS-derived ultrasound markers previously
described are ACUTE indicators of fetal acidemia
Fetal Breathing Movements
Regular fetal breathing noted by 20-21 weeksMore frequent movement during REM sleepDownward movement of the diaphragm, inward chest
wall movementIncreased with hyperglycemiaDecreased with hypoxia, smoking, narcotics, labor
EXAMPLE VIDEO
Biophysical Profile – Scoring9-12
FIVE components Reactive NST Maximum vertical pocket >
2cm or AFI > 5 ≥ 1 episode of breathing lasting
≥ 30s ≥3 discrete body/limb
movements ≥ 1 episode of limb extension
with return to flexion, or opening/closing of hand
Each component is worth TWO points (no partial credit) Normal: ≥ 8/10 (or 8/8 without
NST) Equivocal: 6/10 Abnormal: ≤4/10
NST may be omitted without compromising test validity if the other 4 components = 8/8
9. Chamberlain PF AJOG 1984 10. Manning FA. AJOG 199011. Nabhan AF. Cochrane 200812. Manning FA. AJOG 1987
BPP Management
Score Interpretation Management
10 Low risk for asphyxia Repeat in 7 days, 3-4 days for diabetes or > 41 weeks
8 Low risk for asphyxia Same as above, consider delivery if oligohydramnios
6 Suspect asphyxia 36 wk/favorable Cx or oligo deliver; L/S<2 repeat < 24h
4 Strongly suspect asphyxia
>32 – 34 weeks DELIVER; < 32 wks consider extending or repeating
< 2 Probable asphyxia +/- Extend test time, if still < 4 DELIVER regardless of GA
IMPORTANT LINKS
PRACTICE BULLETIN 145 – Antepartum Fetal Surveillance
OTHER REFERENCES
1. Olesen AG. Acta Obstet Gynecol Scand. 2004
2. Manning FA. AJOG. 1993
3. Porto M. Clin Ob Gyn. 1987
4. Manning FA. Am J Obstet Gynec 1993
5. Manning FA. Am J Obstet Gynec 1987
6. Mangesi L. Cochrane Database Syst Rev 2007
7. Freeman RK. Am J Obstet Gynecol 1982
8. Baschat AA. Ultrasound Obstet Gynecol. 2006
9. Chamberlain PF AJOG 1984
10. Manning FA. AJOG 1990
11. Nabhan AF. Cochrane 2008
12. Manning FA. AJOG 1987