7800 Wolf Trail Cove, Germantown, TN 38138 • (901) 682-9222 • Open Weekdays 8:00 - 5:00
FETAL HEART MONITORING AND UTERINE PRESSURE MONITORING
Fetal heart rate monitoring is the standard method for assessing the well being of the baby during labor. It is now a routine part of the labor and delivery process for most women. Your baby's heart rate will be monitored during labor and delivery so that potential problems can be addressed early. Although fetal heart rate monitoring cannot prevent a problem from occurring, it can help in its early diagnosis and treatment.
Uterine pressure monitoring is another way your physician can get information during labor and delivery. Using this monitoring, your physician can measure the total amount of pressure from each of your contractions. Therefore, he or she can determine if your labor is progressing adequately for the amount of pressure that is being obtained.
Q. What is fetal heart rate monitoring?
A. Fetal heart rate monitoring is a way of measuring trends in your baby's heart rate during labor. There are two ways to perform fetal heart rate monitoring. One is intermittent auscultation. The other is continuous fetal heart rate monitoring. Studies have shown that both are equally effective during labor and delivery.
Intermittent auscultation involves listening to your baby's heart rate on a scheduled regimen. This is often done by a nurse using a hand-held doppler device that is placed against your abdomen. This device uses sound waves to pick up your baby's heart rate. Monitoring is usually done before, during, and after a contraction to see the effect the contraction has on your baby's heart rate.
Continuous fetal heart rate monitoring is the more common form of heart rate monitoring. This type of monitoring uses an electronic device that measures both fetal heart rate and uterine contractions. A printout shows the relationship of the fetal heart rate to the uterine contractions. This allows your physician to continually evaluate changes in your infant's heart rate compared to your contractions.
Two types of continuous fetal monitoring can be used - external and internal. External monitoring involves placing an ultrasound transducer on your abdomen to pick up the fetal heart rate by measuring sound waves. The alternate method is known as internal fetal heart rate monitoring. This type of monitoring requires placing a small device on your baby's scalp after your water has broken. This device more specifically measures the fetal heart rate and may be used if your physician is having difficulty picking up your infant's heart rate with the external monitor.
Q. How is fetal heart rate monitoring used?
A. Fetal heart rate monitoring helps your physician identify certain adverse conditions in pregnancy. For example, if your baby appears to be getting less than adequate oxygenation a certain heart rate is seen. If your baby's umbilical cord is being compressed during labor, another heart rate pattern may be seen. If your baby is having severe metabolic changes--from stress-related to decreased oxygen--another heart rate pattern will be seen. Therefore, by assessing the fetal heart rate patterns and trends, your physician can make decisions and perform interventions that may improve the outcome of your delivery.
Q. What does an abnormal fetal heart rate pattern mean?
A. Basically, the normal fetal heart rate in labor is 120 to 160 beats per minute. Periodic changes in the heart rate during labor are expected, and in fact are considered reassuring. Your doctor may see several types of changes that each have several different meanings. One change is known as early decelerations. This is when there is a small decrease in the fetal heart rate that occurs in coincidence with your contractions. This is not a cause for concern, just a sign that the baby's head is getting mildly squeezed with the contractions. Another finding is called variable deceleration in heart rate. With this type of change a larger decrease in heart rate is often seen with each contraction. This type of deceleration often indicates that your baby's umbilical cord is being squeezed with each contraction. As well, this is usually not a cause for concern unless the heart rate goes very low or is low for a long period of time. Finally, your physician may see late decelerations. These are decreases in the baby's heart rate that occur after the contraction. This can be a cause for concern and may signify that your baby is not getting enough oxygen. Fetal heart rate changes, along with other patterns seen in the heart rate, will give your physician an idea of the well being of your baby.
Q. What is uterine pressure monitoring?
A. Uterine pressure monitoring involves measuring the total amount of pressure created by each of your contractions. This is obtained by placing a small catheter inside your uterus next to your baby. Your physician will measure the Montevideo units (strength of contractions) for 10 minutes. An adequate value is approximately 200 or greater.
Q. How is uterine pressure monitoring used?
A. Uterine pressure monitoring is used to determine if your contraction pattern and strength are adequate for normal progression of labor. If the total number of Montevideo units is low, then your physician may recommend giving you medication to help make your contractions stronger. If your Montevideo units are adequate (greater than 200) for at least 2 hours and your labor is not progressing, your physician may recommend a cesarean section.
Thomas G. Stovall, M.D.
Dr. Stovall is a Clinical Professor of Obstetrics and Gynecology at the University of Tennessee Health Science Center in Memphis, Tennessee and Partner of Women's Health Specialists, Inc.
Date Published: 2004-03-04
7800 Wolf Trail Cove, Germantown, TN 38138
Phone: (901) 682-9222; Fax: (901) 682-9505