Smart Moms | Prenatal Tests

Fetal heart rate monitoring is a part of routine care. Electronic fetal monitoring is a good way to measure your baby's responses to labor and delivery. Electronic fetal monitoring uses equipment to record the heart rate on an ongoing basis. At the same time, the contractions of the uterus are measured. This can be done by feeling the abdomen or by using electronic equipment.

Fetal heart monitoring will be done at different times depending on your stage of labor and if you are at risk for problems. You may be monitored as often as every 5 minutes or every 30 minutes. Or, it may be done continuously. Ask your health care provider about how fetal monitoring will be used during your labor.

Types of Electronic Fetal Monitoring

Electronic fetal monitoring uses electronic equipment to measure the response of the baby's heart rate to contractions of the uterus. It provides an ongoing record that is reviewed by your health care provider.

Electronic fetal monitoring is either external or internal:

External monitoring requires that two small devices be placed on the mother's abdomen. One device uses ultrasound to detect the fetal heart rate. The other measures the length of uterine contractions and the time between them.

Internal monitoring can be used only after the membranes of the amniotic sac have ruptured (that is, after "your water breaks"). A small device called a fetal scalp electrode is inserted through the vagina and attached to your baby's scalp. This device records the heart rate. At the same time, a thin tube called a catheter may be inserted through the vagina into your uterus. The tube measures the strength of contractions. You may feel some discomfort when the tube is inserted. Once it is inserted, though, there is little or no discomfort.

With both external and internal monitoring, information about the mother and the baby is recorded by small machine. The information is printed on a long strip of paper that is read by your health care provider. You may need to stay in bed during both types of monitoring, but you can move around enough to find a comfortable position.

What Do Abnormal Patterns Mean?

An average fetal heart rate varies between 110 and 160 beats per minute. This is much faster than your own heart rate, which is about 60-100 beats per minute.
Changes in the fetal heart rate that occur along with contractions form a pattern. Certain changes in this pattern may suggest a problem. One such problem could be that the umbilical cord, which connects the mother and baby, is being pinched or squeezed.

If there is an abnormal fetal heart rate pattern, you may be:

Asked to change positions
Given oxygen through a mask
Given intravenous fluids
Given medication to decrease the strength of contractions and relax the uterus
Given fluids into the uterus.

Abnormal fetal heart rate patterns do not always mean there is a serious problem, nor do they point to the exact problem. Other tests may be used to get a better idea of what is happening with your baby. Electronic monitoring may be done if abnormal patterns are found with auscultation. If the baby's heart rate patterns don't improve, your health care provider may decide to deliver the baby.

Risks

There are no known risks with auscultation or with external electronic monitoring. With internal electronic monitoring, there is a small risk of infection.

Women who have a high risk for problems during labor and delivery will most likely have electronic fetal monitoring. In women who are high risk or whose babies show an abnormal heart rate pattern with electronic fetal monitoring, the delivery of the baby is more likely to be by cesarean birth or with special instruments (such as forceps or a suction device).

Finally . . .

Fetal heart rate monitoring is just one of the many ways used to check the progress of your labor and the well-being of your baby. A number of factors are involved in deciding what type suits you best. You should discuss your questions about fetal monitoring with your health care provider when preparing for the birth of your baby.