The paper is then looked at to determine if the heart rate elevations where high enough and occurred frequently enough. Sometimes fetuses are sleeping quietly. They may not have heart rate elevations for up 80 minutes. A buzzing device may be used to wake the fetus up. Waiting usually results in the fetus waking up.
Younger fetuses take longer to wake up.
When women are in the hospital, they are often done daily. The BPP uses ultrasound to evaluate how a fetus is moving. Fetuses are like small children, when they are sick they do not move much, and lie limply. The amount of fluid around the fetus. The muscle tone of the fetus.