Ultrasound may be used to observe the baby for about 30 minutes. During this time, the rhythmic movements of the chest are monitored and movements are counted to evaluate fetal well-being. If you are having contractions, an external tocodynamometer records their pattern. To assess a baby's heart rate and other vital signs during delivery, a thin catheter containing two small electrodes is inserted through the cervix. The electrodes are attached to the baby's scalp, and the catheter is then removed.
Alternative methods use an external ultrasound monitor.
During labor, fetal blood may be drawn from the baby's scalp and checked for acidity. After the test - No special aftercare is required. Factors affecting results Certain drugs, including painkillers, anesthetics, and tranquilizers. Position at which external fetal monitor is placed. Body position and obesity.