A nonstress test is a safe, noninvasive test for pregnant women. Noninvasive means it doesn't cut into the skin or enter any part of the body. The test measures the heart rate of an unborn baby as the baby moves in the uterus. In most healthy babies, the heart rate, also known as the fetal heart rate, increases during movement. If your nonstress test results showed that the heart rate was not normal, it may mean that your baby is not getting enough oxygen. If this happens, you may need more testing or treatment, or in some cases, delivery may be induced.