Medical advances in technology continue to make monitoring fetal development easier, as well as help detect health problems early in the pregnancy to protect both the mother and the baby. One of the most common devices used for this purpose is the fetal monitor, which allows your doctor to gauge the health of your baby as it develops.
Monitor Basics
Fetal monitors typically are reserved for later in your pregnancy once a fetal heart rate is strong enough to monitor. Most often they are used during labor after the start of uterine activity and contractions. To use the monitor, two belts are secured around your abdomen. Each belt has a monitoring function, with the first belt used to measure your baby's heart rate and the second containing a tocodynamometer which measures uterine activity.
Fetal Heart Rate
The heart monitoring belt utilizes a conductive gel placed on your abdomen. A tranducer in the belt emits ultrasound, or sound waves, through the gel and your abdomen toward your baby's heart. The waves then bounce back toward the belt and allow an electronic monitor to measure and monitor the speed and strength of the fetal heart rate. The results are displayed on a monitor screen, as well as printed out on graph paper simultaneously. In some cases a fetal heart rate monitor may be inserted internally, but the procedure can have side effects because the doctor must rupture the fetal membranes to connect the monitor electrode to the baby's head.
Uterine Activity
The second belt is placed directly over the uterus and utilizes a sensor on the underside of the tocodynamometer which presses up against your abdomen. When you have a uterine contraction, the contraction presses against the sensor and allows the monitor to track how far apart contractions are during labor. A fetal monitor can also be used internally to measure contractions by inserting an intrauterine pressure catheter to more accurately measure the strength of the contractions, which cannot be measured from an external monitor.
Importance
Fetal monitoring plays an essential role in ensuring the healthy delivery of your baby. Measuring fetal heart rate is common as part of pregnancy testing, specifically nonstress tests. During a nonstress test, the fetal heart rate is measured with each fetal movement. A loud noise is produced to encourage the baby to move; his heart rate should increase as he moves. However, if the heart rate does not increase, it may indicate the baby is not getting adequate oxygen from the placenta and further tests must be performed. During delivery, the fetal monitor measures the strength and frequency of contractions -- an important indicator of how far along the labor is. A fetal monitor also can detect the occurrence of a placental abruption -- a serious condition in which the placenta detaches from the uterus.
