Fluctuations in the fetal heart rate are positive. We interpret this as a reactive NST. In some cases, the desired criteria are not seen on the test because the baby is asleep or has restricted movement due to a problem, and then the condition called Non-reactive NST occurs. A sleeping baby is awakened with sounds or movements, and the NST improves. However, if there is a medical problem that jeopardizes the baby's well-being, the NST will not improve.