A biophysical profile (BPP) test measures the health of your baby (fetus) during pregnancy. A BPP test may include a nonstress test with electronic fetal heart monitoring and a fetal ultrasound. The BPP measures your baby's heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid around your baby.

A BPP is commonly done in the last trimester of pregnancy. If there is a chance that your baby may have problems during your pregnancy (high-risk pregnancy), a BPP may be done by 32 to 34 weeks or earlier. Some women with high-risk pregnancies may have a BPP test every week or twice a week in the third trimester.

Why It Is Done

A biophysical profile (BPP) test is done to:

• Learn about and keep track of your baby's health. Special ultrasound methods are used to keep track of movement, increases in heart rate with movement (nonstress test), muscle tone, breathing rate, and the amount of amniotic fluid surrounding your baby. If these five areas are within a normal range, your baby is considered to be in good health.
• Check on your baby's health if you have:
  • Hyperthyroidism.
  • Bleeding problems.
  • Lupus.
  • Chronic kidney disease.
  • Type 1 diabetes or gestational diabetes.
  • High blood pressure (hypertension).
  • Preeclampsia.
  • A small amount of amniotic fluid (oligohydramnios) or too much amniotic fluid (polyhydramnios).
  • A multiple pregnancy (such as twins or triplets).

How To Prepare

Usually a full bladder is needed for the test. If so, you will be asked to drink water or other liquids just before the test and to avoid urinating before or during the test.

If you smoke, you will be asked to stop smoking for 2 hours before the external monitoring test because smoking decreases your baby's activity.

Talk to your health professional about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

How It Is Done

Most often, a biophysical profile (BPP) is performed by your obstetrician. However, it may be done by an ultrasound technologist or radiologist. A BPP can be done in your doctor's office, hospital, or clinic.

A nonstress test with electronic fetal heart monitoring and a fetal ultrasound may be done at the same time as a biophysical profile. See an illustration of fetal ultrasound and external monitoring. A modified biophysical profile combines a nonstress test and measurements of the amniotic fluid.

Nonstress test

External fetal heart monitoring records your baby's heart rate while your baby is moving and not moving. It is usually done just before a fetal ultrasound.