Q&A: What Is Fetal Acoustic Stimulation?

Fetal acoustic stimulation is pretty much what it sounds like: It's when we wake up your fetus with sound — and a little vibration too. Docs use it during a nonstress test, in which they monitor the placenta to make sure it's functioning. In the nonstress test, they'll put a heart-rate monitor on your belly to see how your fetus's heart rate changes when he moves. If he's asleep, they'll press the fetal acoustic stimulation device on your belly to wake him up, so he starts moving again, and they can read his heart rate.