A biophysical profile (BPP) test measures the health of your baby (fetus) during pregnancy. A BPP test may include a non stress 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. It is usually done to keep track of your baby’s health.