What is a fetal nonstress test?
The nonstress test is a way of monitoring your baby’s health through your skin. This is not an invasive test, meaning it is not performed internally. A nonstress test allows your health care provider to check if your baby’s heart rate pattern is one seen in healthy babies. It checks to see that the heart rate increases when the baby moves around.
The nonstress test usually is performed between 38 and 42 weeks of pregnancy, especially when you’re past your due date, to make sure all’s well with the baby. It can be done as early as the 27th week of pregnancy, if your health care provider feels there are reasons to take a closer look.
For this test, you will sit with knees and back partially elevated, sometimes with a cushion under the right hip to help shift your uterus to the left. Sensitive electrodes (connected to monitors) are placed on your abdomen over conducting jelly. The electrodes can sense the fetal heart rate (FHR) and the presence and length of any uterine contractions. Usually, the results of this test appear on a computer screen, or they are printed out. If there are contractions, the external monitors will show them but they won’t be able to tell how strong they are.
If there is no fetal heart rate increase from being moved around after 30 – 40 minutes, your baby may be napping. Seriously, babies do go to sleep! If that’s the case, you will be given something sweet to drink or a small meal which may perk your baby up and get him moving. If that doesn’t work, the use of fetal acoustic stimulation (sending loud noise to the baby) may work as may gently placing your hands on your abdomen and moving the baby from side to side. Wake up little one!
If your baby still is not as responsive as your health care provider would like to see, you may move on to either a biophyiscal profile (taking a closer look with detailed ultrasound), a stress test (testing to see how your baby responds to contractions) or even delivery.