Fetal Monitors - The Beginning and Use
Fetal monitors were first used in 1958 at Yale University. Today, they are a standard component of the process of labor and delivery. Fetal monitoring can potentially provide valuable information about the condition of the baby in the uterus - such as a slowing of the baby's heart rate due to lack of oxygen which may indicate a problem with the umbilical cord or difficulty during labor. The problem enters if the person who is doing the reading of the fetal monitor strips does so incorrectly. The risk of an incorrect diagnosis of an emergency situation or condition presents some serious issues. Nurses and doctors take fetal monitoring classes and fetal monitoring courses in order to be able to be accurate when reading a fetal monitor strip. There is a fetal monitoring certification process as well to ensure that those nurses and technicians who are using the monitoring systems are qualified to do so.
What's the Purpose of a Fetal Monitor?
The fetal monitor's main purpose in terms of labor and delivery is to keep track of the baby's heartbeat during contractions as well as to monitor the contractions themselves. External fetal monitoring is done through the placing of a small round ultrasound disc with ultrasound gel (to conduct the sound waves) to the abdomen that is held in place with a lightweight stretchy band. A pressure-sensitive device is also placed on the abdomen by a stretchy band and this measures the frequency and length of contractions, but not their strength. The combination of both monitoring tools helps the labor and delivery team know more about how the baby is withstanding the labor. They are not left on the woman's abdomen if the information gained from reading the fetal monitoring strips indicates that all is well. They will be used again at a later point, but they are not left on the woman's body unless there are signs of distress.
Checking For Fetal Movement, Contraction Strength and Heartbeat
Another way to check for fetal movement and heart monitoring is done earlier in the pregnancy, as early as the 27th week. It is called a non-stress test and it measures the fetal heart rate accelerations with normal movement as well as uterine contractions. If the baby's movements do not cause a rise in its heartbeat after 30 minutes, then stimulation with be given to encourage movement.
The contraction stress test is the measuring of the placenta's ability to provide adequate oxygen to the baby during contractions. The same monitors used to measure uterine contractions and fetal heart rate are used and stimulation is used to initiate contractions if they are not coming hard enough or often enough to register a reading. Fetal circulation operates differently in the uterus than it does outside. In the womb, the baby receives everything necessary, including oxygen, through the umbilical cord and from the mother. Because the placenta does the work of exchanging oxygen and carbon dioxide through the mother's circulation, the fetal lungs are not used for breathing. When the cord is clamped at birth, the detachment from the placenta and the first breaths of air taken by the baby at birth change the circulation system and the baby begins to pump blood through the heart by itself.
If external fetal monitoring is not working well or the information they are getting from the fetal monitoring strips seems to be suspicious, then internal fetal monitoring may be used. A small electrode is attached to the baby's scalp, after the water has broken, to directly monitor the baby's heartbeat. The electrode's wire is strapped to the thigh of the woman and attached to the monitor for reading.
Is It Necessary?
There has recently been a revision to the guidelines of fetal monitoring during labor and delivery. Fetal monitoring was originally introduced with the hope that it would lead to a reduction in the risks of cerebral palsy and death resulting from inadequate oxygen to the fetal brain. However, it became part and parcel of the birthing process being implicated in the increase of Caesarean births because there were no clear cut guidelines on interpretation of findings. It has not reduced the risk of either cerebral palsy or fetal deaths but it has been a cause for increased costs of malpractice insurance due to the increase in c-sections and forceps deliveries. New guidelines have been introduced and implemented regarding the reading of data with the hope that it will help the doctors make better decisions during labor about when or if to intervene.