One of the most important tools that doctors have available to them to check on the well-being of a baby during labor is the fetal heart rate monitor, which has been in use for several decades. It definitely improved the ability of doctors to find out if a baby is having problems during the labor process and, if so, to intervene and perform an emergency C-section.
The equipment consists of a belt that fits around the pregnant mother's abdomen. The belt contains a sensor that can detect contractions and the heart beat of the baby. The belt is connected to an electronic monitor that prints out a graph showing the mother's contractions and the baby's heart beat. While the baby is healthy, there is a certain distinct pattern that the heart beat shows. There will be periods of acceleration and then deceleration. Doctors are trained to look at the graph and see if the pattern of the heart rate is normal. There are certain signs on the graph that can indicate that the baby may be experiencing difficulty or what the doctors call "fetal distress." For example, if the heart rate gets very low or if it does not respond well and recover from the mother's contractions, these may be signs that the baby is having trouble tolerating the labor process. In such a situation the doctor should perform an emergency C-section to rescue the baby from this difficult environment.
By far, the biggest danger that any baby can face during the labor process is a doctor not recognizing the signs of fetal distress and performing an emergency C-section. If fetal distress goes on for too long, the baby's brain is deprived of oxygen that is so critical to his or her well-being. If the oxygen supply is interrupted for long enough, it can cause devastating brain damage leading to cerebral palsy or other neurological problems in the child.
A mother's labor can often last several hours, and the doctor is certainly not at the bedside continuously looking at the fetal monitor. Instead, it is the nurses who spend most of the time looking at the printout of the baby's heart beat, and they are trained to be alert for signs of fetal distress. If it occurs, they are to immediately notify the doctor. Obviously, the doctor will routinely come in and see the patient several times during labor and at each of those visits he or she should be closely inspecting the printout from the fetal monitor to make sure there are no signs of fetal distress.