Fetal monitors are medical instruments used to constantly register the heart rate and other functions of the fetus during late pregnancy and labor. The monitoring process involves checking the rate, rhythm, and evaluating if there is any unusual increase or decrease in the heart rate as the fetus responds to conditions in the uterus. An abnormal heart rate may indicate that an emergency cesarean delivery is needed. External and non-invasive fetal monitors use a Doppler ultrasound device and has no associated complications. Internal fetal monitors, on the other hand, have higher accuracy but can only be used once the water breaks and the cervix opens. Hospitals and healthcare providers utilize fetal monitors to detect problems early on and provide the best possible treatment and care.