Biophysical Profile (BPP)

What is a biophysical profile (BPP)?

A biophysical profile (BPP) is a test that combines a nonstress test with ultrasound. A nonstress test (NST) measures the fetal heart rate in response to the movements of the fetus. An ultrasound is a diagnostic technique that uses high-frequency sound waves to create an image of the internal organs. Biophysical profile testing is usually performed in the last trimester of pregnancy.

There are five parts to a biophysical profile:

• the nonstress test

plus four areas assessed by ultrasound:

• fetal breathing movements

• fetal movements

• fetal tone

• amniotic fluid volume

How is a biophysical profile performed?

Each of the five areas of the biophysical profile has a possible total score of two points, for a total of 10 points. A score of:

• eight to ten is usually considered normal.

• six is considered equivocal (uncertain).

• four or less is considered abnormal.

If the score is questionable or abnormal, or if the amniotic fluid volume is too low, additional testing may be needed.

What is a modified biophysical profile?

Another type of BPP is sometimes performed. The modified BPP combines the nonstress test and an evaluation of the amount of amniotic fluid called the amniotic fluid index (AFI). A pocket of amniotic fluid is measured using ultrasound, then the total amount of amniotic fluid is estimated.