External Fetal Monitoring (EFM) is a non-invasive test performed on occasion during pregnancy. If you are given an EFM, you'll sit in a slightly reclined doctor's chair with your knees and back partially elevated and a cushion under the right hip (this helps shift your uterus to the left).
Next, a nurse will put some conducting jelly over your abdomen and position highly sensitive electrodes (or monitors) over the conducting jelly to listen for your baby's fetal heart rate (FHR) and to check for the strength and duration of any uterine contractions. Usually, the results of this test are continuous and are printed out or appear on a computer screen.
EFM allows your doctor to see if your baby is experiencing any fetal distress. It will also help her see how and if your baby is being affected by your contractions.