Biophysical clinic
What is Biophysical test?
The biophysical profile is a test done after the 28th week of pregnancy. This noninvasive diagnostic test helps evaluate the fetus. It measures body movement, muscle tone, breathing movement and amniotic fluid volume around the fetus.
What is the biophysical profile?
The biophysical profile is a noninvasive prenatal diagnostic test that usually is performed after the 28th week of pregnancy to evaluate the well-being of the fetus. It combines an ultrasound examination with a non-stress test. The non-stress test is performed to assess fetal heart rate acceleration in response to movement. The ultrasound test is designed to assess four components:
- Fetal gross body movement: Separate movements of the body or limbs, including fine motor movements
- Fetal muscle tone: Opening or closing of the hands and mouth, extension and flexing of the limbs, or repositioning or rotation of the trunk of the body
- Fetal breathing movements: Continuous, rhythmic breathing episodes
- Amniotic fluid volume: A single pocket of amniotic fluid that measures at least one centimeter across and two centimeters vertically
In some cases, a modified biophysical profile may be performed instead of the complete biophysical profile. The modified biophysical profile combines a nonstress test with an ultrasound assessment of the amount of amniotic fluid.
Why is the biophysical profile performed?
The biophysical profile may be ordered for women with high-risk pregnancies, pregnancies that last beyond 40 weeks, or in other situations where there may be complications during gestation.
The indications for a biophysical profile include
- Long-term maternal diseases, such as hypertension, lupus, renal disease, or thrombocytopenia
- Decrease in fetal movement
- Previous stillbirth or other negative outcome
- Multiple gestation (more than one fetus)
- Pregnancy-related hypertension (high blood pressure) or preeclampsia
- Possible intrauterine growth restriction
- Diabetes before pregnancy or diabetes associated with pregnancy (gestational diabetes)
- Late term pregnancy (at or beyond 41 weeks)
- Moderate or severe asthma
How are components scored during the biophysical profile?
The biophysical profile will yield a maximum score of 10 points, if all criteria are satisfied. Each of the components receives a score of two points, unless the results are abnormal. The criteria for each component are listed below.
- Non-stress test: At least two episodes of fetal heart rate acceleration during a 20-minute period
- Fetal gross body movement: Three or more separate movements of the fetal body or limbs over 30 minutes
- Fetal muscle tone: One or more episodes of active extension and flexion of an arm or leg, or the opening and closing of a hand, during the 30-minute test
- Fetal breathing movements: At least one episode of continuous fetal breathing that lasts at least 30 seconds during the 30-minute test
- Amniotic fluid volume: A single pocket of amniotic fluid that measures at least one centimetre across and two centimetre vertically