Biophysical Profile (BPP)

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.

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).

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?).

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.

External monitoring is done using two flat devices (sensors) held in place with elastic belts on your belly. One of these uses reflected sound waves (ultrasound) to keep track of your baby's heart rate; the other measures the duration of your contractions. The sensors are connected to a machine that records the information. Your baby's heartbeat may be heard as a beeping sound or printed out on a chart.

If your baby moves or you have a contraction, you will be asked to push a button on the machine. Your baby's heart rate is recorded and compared to the record of movement or your contractions. This test usually lasts about 30 minutes.

Fetal ultrasound

Often you do not need to remove your clothes for the ultrasound test; you can lift your shirt and push down the waistband of your skirt or pants. If you are wearing a dress, you will be given a cloth or paper covering to use during the test.

• You may need to have a full bladder. You may be asked to drink 4 to 6 glasses of liquid, usually juice or water, about an hour before the test. A full bladder helps transmit sound waves and pushes the intestines out of the way of the uterus. This makes the ultrasound picture clearer.
  • You will not be able to urinate until the test is over. However, tell the ultrasound technologist if your bladder is so full that you are in pain.
  • If you cannot drink enough liquid, your bladder may be filled with sterile water through a thin flexible tube (urinary catheter) inserted through your urethra.
  • If an ultrasound is done during the later part of pregnancy, a full bladder may not be needed. The growing fetus will push the intestines out of the way.
• You will lie on your back on a padded examination table. If you become short of breath or lightheaded while lying on your back, your upper body may be raised or you may be turned on your side.
• A gel will be spread on your abdomen.
• A small, handheld instrument called a transducer will be pressed against the gel on your skin and moved across your abdomen several times. You may watch the monitor to see the picture of the fetus during the test.

When the test is finished, the gel is cleaned off of your skin. You can urinate as soon as the test is done. Transabdominal ultrasound takes about 30 to 60 minutes.

Ultrasound technologists are trained to gather images of your fetus but cannot tell you whether it looks normal or not. Your health professional will share this information with you after the ultrasound images have been reviewed by a radiologist or perinatologist.

Lying on your back (or side) during the test may be uncomfortable. During a fetal ultrasound, you may have a feeling of pressure in your bladder. The gel may feel cool when it is first applied to your stomach. You will feel a light pressure from the transducer as it passes over your abdomen.

There is very little chance of either the mother or the baby having a problem from a biophysical profile (BPP). However, you may feel anxious if the ultrasound reveals a problem with your pregnancy or baby. A nonstress test may falsely show distress in a baby that is actually healthy.

A biophysical profile (BPP) test measures the health of your baby (fetus) during pregnancy. The results are scores on five measurements in a 30-minute observation period.

A score of 8 to 10 points means that your baby is healthy. A score of 6 to 8 points means that you may need to be retested in 12 to 24 hours. A score of 4 or less may mean the baby is having problems. Further testing will be recommended.

Reasons you may not be able to have the test or why the results may not be helpful include:

• The baby is in a position that makes an ultrasound difficult.
• Being unable to lie still throughout the procedure, which can cause the picture of your baby to be unclear.
• Being overweight, which may make it difficult to correctly position the external monitoring device.
• An infection in either you or your baby.
• Low (hypoglycemia) or high (hyperglycemia) blood sugar levels.
• Medicine, such as magnesium sulfate.
• Steroids given to help the baby's lungs mature.
• Alcohol or illegal drugs, such as cocaine.
• In rare cases, stool (feces) or air in the intestines or rectum interfering with the fetal ultrasound.

• A biophysical profile includes a nonstress test with electronic fetal heart monitoring and a fetal ultrasound. For more information, see the medical tests Electronic Fetal Heart Monitoring and Fetal Ultrasound.
• Additional tests, such as a contraction stress test, may be recommended if your results are not normal. For more information, see the medical test Contraction Stress Test.
• If there is a chance that you or your baby may have problems during your pregnancy, you may have a biophysical profile test every week or twice a week during the last 12 weeks of your pregnancy. Your chances of having problems may be higher if you have:
  • Certain medical conditions, such as high blood pressure, kidney disease, diabetes, preeclampsia, or autoimmune diseases.
  • A history of a stillbirth or preeclampsia.
  • A history of Rh incompatibility.
  • A history of early labor, premature rupture of membranes (PROM), or placenta problems.
  • If your baby seems small for the length of the pregnancy or is not growing (intrauterine growth retardation or restriction).
• A biophysical profile may be done after an injury, such as a car crash or fall. Your doctor may recommend additional BPP tests during the rest of your pregnancy.
• Research is being done on the usefulness of BPP testing during labor. Low BPP test scores may help predict the need for a cesarean section or whether a baby will need specialty care after delivery.

• Electronic Fetal Heart Monitoring
• Fetal Ultrasound

Other Works Consulted

• Chernecky CC, Berger BJ, eds. (2004). Laboratory Tests and Diagnostic Procedures, 4th ed. Philadelphia: Saunders.

• Fischbach FT, Dunning MB III, eds. (2004). Manual of Laboratory and Diagnostic Tests, 7th ed. Philadelphia: Lippincott Williams and Wilkins.

• Handbook of Diagnostic Tests (2003). 3rd ed. Philadelphia: Lippincott Williams and Wilkins.

• Pagana KD, Pagana TJ (2006). Mosby’s Manual of Diagnostic and Laboratory Tests, 3rd ed. St. Louis: Mosby.

• Young SK, et al. (2003). Is the intrapartum biophysical profile useful? American Journal of Obstetrics and Gynecology, 102(3): 471–476.