Biophysical profile


A biophysical profile is a prenatal ultrasound evaluation of fetal well-being involving a scoring system, with the score being termed Manning's score. It is often done when a non-stress test is non reactive, or for other obstetrical indications.
The "modified biophysical profile" consists of the NST and amniotic fluid index only.

Procedure

The BPP has five components: four ultrasound assessments and an NST. The NST evaluates fetal heart rate and response to fetal movement. The five discrete biophysical variables are:
  1. Fetal heart rate
  2. Fetal breathing
  3. Fetal movement
  4. Fetal tone
  5. Amniotic fluid volume
ParameterNormal Abnormal
NST/Reactive FHRAt least two accelerations in 20 minutesLess than two accelerations to satisfy the test in 20 minutes
US: Fetal breathing movementsAt least one episode of > 30s or >20s in 30 minutesNone or less than 30s or 20s
US: Fetal activity / gross body movementsAt least three discrete body/limb movement in 30 minutes or trunk, opening and closing of hand considered to be normal tone.Either slow extension with return to partial flexion or movement of limb in full extension or absent fetal movement.
US: Qualitative AFV/AFIAt least one vertical pocket > 2 cm in the vertical axis or AFI of 5 cmLargest vertical pocket

Use of vibroacoustic stimulation to accelerate evaluation has been described.

Interpretation

Each assessment is graded either 0 or 2 points and then added up to yield a number between 0 and 10. A BPP of 8 or 10 is generally considered reassuring. A BPP normally is not performed before the second half of a pregnancy since fetal movements do not occur in the first half.
The presence of these biophysical variables implies absence of significant central nervous system hypoxemia/acidemia at the time of testing. By comparison, a compromised fetus typically exhibits loss of accelerations of the fetal heart rate, decreased body movement and breathing, hypotonia, and, less acutely, decreased amniotic fluid volume.
BPPRecommended management
≤2
4
  • Labor induction if gestational age >32 weeks
  • Repeating test same day if <32 weeks, then delivery if BPP <6
    • 6
  • Labor induction if >36 weeks if favorable cervix and normal AFI
  • Repeating test in 24 hours if <36 weeks and cervix unfavorable; then delivery if BPP <6, and follow-up if >6
    • ≥ 8
  • Labor induction if presence of oligohydramnios