The biophysical profile (BPP) was developed in 1979 by Drs Lawrence Platt and Frank Manning. It is an assessment of five biophysical variables: breathing movement, body movement, tone, amniotic fluid volume, and FHR (fetal heart rate) reactivity. The BPP is used to assess the health of the fetus.
Breathing and body movement, tone, and amniotic fluid volume are assessed by ultrasound scanning. FHR reactivity is assessed with the NST (nonstress test). By combining these assessments, the biophysical profile helps to identify the compromised fetus and confirm the healthy fetus.
The BPP is most useful in the evaluation of women who experience decreased fetal movement (who might subsequently have a nonreactive NST) and in the management of diabetic, IUGR, and postterm pregnancies.
Biophysical Profile Scoring
Techniques and Interpretation
A score of 2 is assigned to each normal finding and 0 to each abnormal one for a maximum score of 10.
Normal findings (score = 2)
- Breathing movements: ≥ 1 episode of ≥ 20 seconds in 30 minutes.
- Body movements: ≥ 2 discrete body/limb movements in 30 minutes (episodes of active continuous movement is considered as a single movement).
- Tone: ≥ 1 episode of active extension with return to flexion of limb(s) or trunk (opening and closing of the hand is considered normal tone).
- Amniotic fluid volume: ≥ 1 pocket of fluid measuring ≥ 2 cm in 2 perpendicular planes.
- FHR reactivity: ≥ 2 episodes of acceleration of ≥ 15 bpm and of > 15 seconds associated with fetal movement in 20 minutes.
Abnormal findings (score = 0)
- Breathing movements: Absent or no episode of ≥ 20 seconds in 30 minutes.
- Body movements: < 2 episodes of body/limb movements in 30 minutes.
- Tone: Either slow extension with return to partial flexion, movement of limb in full extension, absent movement, or partially open hand.
- Amniotic fluid volume: Either no pockets or a pocket < 2 cm in 2 perpendicular planes.
- FHR reactivity: ≥ 1 episode of acceleration of FHR or acceleration of < 15 bpm in 20 minutes.
Management Protocol for Biophysical Profile Scoring
Scores of 8 and 10 are considered normal (unless a decrease in amniotic fluid is noted, in which case the infant may need to be delivered). Repeat testing is normally done weekly (some patients, such as diabetics and patients ≥ 42 weeks, are tested twice a week).
Scores of 4 and 6 are suspicious for chronic asphyxia. Repeat testing is normally done in 24 hours. If the repeat test is ≤ 6, delivery may be recommended.
Scores of 0 and 2 are strongly suspicious of chronic asphyxia. Testing time is usually extended to 120 minutes. A persistent score of ≤ 4 indicates delivery.
The advantages of the biophysical profile are numerous. It is reliable and non-invasive, requires a short time to assess the components, does not depend on accurate gestational age dating, does not require the woman to have a full bladder, and can reduce the use of the CST (contraction stress test) in women who have nonreactive NST.
Baby Center: Biophysical profile - https://www.babycenter.com/0_biophysical-profile_1276703.bc
eMedicine: Biophysical Profile, Ultrasound - https://emedicine.medscape.com/article/405454-overview
Image courtesy of https://en.wikipedia.org/wiki/File:Ultrasound_Scan_ND_084.jpg