Nonstress test

A nonstress test is a simple, noninvasive procedure done at 32 weeks' gestation or later; it is performed in the doctor's office or in the labor-and-delivery department at the hospital. This test measures how the fetal heart responds to the fetus's own movements and evaluates fetal well-being in late pregnancy. It is commonly used in overdue and high-risk pregnancies. Information gained from a nonstress test gives reassurance that your baby is doing OK.

How the Test Is Performed
While you are lying down, a monitor is attached to your abdomen. Every time you feel the baby move, you push a button to make a mark on the monitor paper. At the same time, the fetal monitor records the baby's heartbeat on the same paper.

Test Results
Each time the baby moves, the heart rate should accelerate by about IS beats for about IS seconds. When this occurs twice in a 20minute period, the test is considered normal or reactive. If the baby doesn't move or if the heart rate does not react to movement, the test is called nonreactive. This doesn't necessarily mean there is a problem-the baby may be sleeping. In more than 75% of nonreactive tests, the baby is healthy.

A nonreactive test is not reassuring. In this case, you will probably have to repeat the test in 24 hours or have additional tests, including a contraction stress test or a biophysical profile.