Fetal biophysical profile

Fetal biophysical profile score (BPS or BPP) refers to assessment of four discrete biophysical variables by ultrasound. It is often a standard tool in antepartum fetal assessment. It is usually assessed after 28 weeks of gestation.

Radiographic assessment

Antenatal ultrasound

The ultrasound variables includeare

1. fetal breathing: considered abnormal if there is
   • absent breathing 
   • no breathing episode for ≥ 20 seconds within a 30 minute lapse
2. fetal tone: considered abnormal if there is 
   • slow extension with return to partial flexion
   • absent fetal movement
3. fetal movement (gross body movement): considered abnormal if there is 
   • < 2 episodes of body/limb movements within a 30 minute lapse
4. amniotic fluid volume: considered abnormal if the the largest  pocket is < 2 x 2 cm

Each of these parameters is given a score of either 0 or 2 points where an abnormal score gets 0 while a normal score gets 2.

Therefore on ultrasound assessment, a total score is given out of 8. An overall abnormal score out of 8 is often taken as4/8 or less.

In addition to this, an additional non sonographic variable (non stress test) with two extra points can also be taken into account. In which case a score is given out of 10.

Potential confounding variables

Some reports show maternal fasting resulting in reduced fetal breathing  movementsmovements which can in turn affect the BPP score ⁵. 

Additional work up

Umbilical arterial Doppler assessment is usually additionally carried out to evaluate fetuses with abnormal BPP scores.

History and etymology

The score was Initiallyinitially proposed by F A Manning et al in 1980 ³.