The American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins–Obstetrics recently released a practice bulletin on fetal heart rate monitoring. ACOG Practice Bulletin No. 62 was published in the May 2005 issue ofObstetrics and Gynecology.
Electronic fetal heart rate monitoring is used to determine whether a fetus is well oxygenated. It is being used increasingly for pregnant women in the United States (62 percent of pregnant women in 1988, 74 percent in 1992, and 85 percent in 2002). Fetal heart rate monitoring can be performed internally or externally.
According to the ACOG committee, the false-positive rate of electronic fetal monitoring for predicting adverse outcomes is high. Data showed that the use of electronic fetal monitoring increased the likelihood of cesarean delivery and the use of vacuum or forceps operative vaginal deliveries when compared with intermittent auscultation. Electronic fetal monitoring does not appear to reduce the incidence of cerebral palsy or overall perinatal mortality, although perinatal mortality caused by fetal hypoxia seems to be reduced.
The practice bulletin recommends that the heart rate of patients without complications be reviewed every 30 minutes during the first stage of labor and every 15 minutes during the second stage. For patients with complications (e.g., fetal growth restriction, preeclampsia), fetal heart rate should be reviewed every 15 minutes during the first stage of delivery and every five minutes during the second stage. Patients with high-risk conditions should be monitored continuously during labor. The ACOG committee recommends that physicians document and store the fetal heart rate tracings.
An ancillary test of fetal status, fetal pulse oximetry, is associated with a significantly lower rate of cesarean delivery. However, because of concerns about false reassurance of fetal oxygenation, use of fetal pulse oximetry is not recommended at this time.