A non-stress test (or NST) received its name because there is no stress placed on the fetus; it is a noninvasive procedure performed after 28 weeks gestation in high risk pregnancies. During an NST, two belts are attached to the mother’s abdomen – one to measure the baby’s heartrate, and one to measure the uterine contractions. The “reactivity” of the heart rate is compared to the baby’s movements. Sometimes, the baby may be sleeping, and the doctor or nurse may use a “buzzer” to wake the baby up to complete the test. There are no risks to an NST, and the test will help determine if the baby is receiving enough oxygen or if s/he is in any distress.4 This can be performed in the doctor’s office, in the hospital, or sometimes at a patient’s home.
A Biophysical Profile (or BPP) is a combination of an ultrasound with a non-stress test. An ultrasound technician will watch your baby during the NST, and will measure breathing, movement, heart rate, muscle tone, and amniotic fluid. The measurements will result in a score which will assist in determining the health of your baby. A BPP is typically done after 32 weeks gestation, and poses no risks *with the exception* of some concerns that have been raised about repeated ultrasounds.5