Elastic band, stockinette or abdominal strap. Description of test You or a close relative will be required to sign a consent form after the procedure has been explained to you. Procedure is painless and does not involve any penetration of the skin. It will not hurt the fetus or interfere with the normal progress of labor. You may have to restrict movement during baseline readings, but you may change position during other readings.
Ultrasound transducer is strapped over the area where fetal heart sounds are most distinct.
Sounds are converted into graphic images and printed out for continuing observation. During labor, pressure transducer is strapped onto the abdomen to record strength and duration of each uterine contraction. If fetal heart rate returns to normal, labor may continue. If abnormal FHR patterns persist, Cesarean birth may be required. If baby is not delivered, external fetal monitoring should be done weekly before delivery in some cases, such as pregnancy over 42 weeks, when fetal growth is delayed or during premature labor, if contractions are strong and cervical dilatation begins.