A biophysical profile (BPS or BPP) is a test typically performed after 32 weeks of pregnancy to evaluate the fetus’s health. It’s often done when your pregnancy is high risk due to health conditions or you have irregular test results. It helps answer questions your healthcare provider has about your fetus’s well-being.
Pregnancy care providers perform a biophysical profile with an ultrasound. It looks at four different areas to come up with a score. A biophysical profile is noninvasive and low risk. It uses a scoring system to rate the fetus in these areas:
Body movement: The fetus moves its limbs or body
Muscle tone: The fetus opens and closes its hands or bends and extends its arms or legs
Breathing movements: The fetus has continuous, rhythmic breathing
Amniotic fluid volume: There’s a pocket of amniotic fluid that measures at least 1 centimeter (cm) across and 2 centimeters vertically.
There are times that a nonstress test (NST) is needed if one or more of the areas aren’t met. This test looks for accelerations in the fetus’s heart rate.
Your pregnancy care provider may order a biophysical profile if your pregnancy is high risk or goes beyond 40 weeks. They may also suggest a biophysical profile if you have any of the following conditions:
Hypertension, lupus, renal disease or thrombocytopenia
There’s a decrease in the fetus’s movements
Previous stillbirth or other negative pregnancy outcomes
Expecting multiples (twins or triplets)
Pregnancy-related hypertension (high blood pressure) or preeclampsia.
Possible intrauterine growth restriction. (The fetus is measuring smaller than average.)
Diabetes before pregnancy or diabetes associated with pregnancy (gestational diabetes).
Too much or too little amniotic fluid.
You’re 35 or older at the time of delivery.
There are five parts to a biophysical profile. The first is a nonstress test, which assesses the fetus’s heart rate in response to its movement or contractions.
The other four parts are assessed by ultrasound. They include looking at:
The fetus’s breathing movements
The fetus’s body movements
The fetus’s muscular tone, such as flexing and extending limbs
The amount of amniotic fluid. Amniotic fluid is a water-like substance that surrounds the fetus in your uterus
