Many hospitals advertise their high-tech fetal monitoring system as evidence of the safety of delivering at their facilities. However, two recent studies found that neither central fetal heart monitoring nor fetal oxygen monitoring improved perinatal outcomes or reduced the rate of cesarean section.

Researchers at the University of Buffalo and Women and Children's Hospital of Buffalo conducted a retrospective study to evaluate whether central fetal monitoring influences perinatal outcomes and the cesarean section rate. They compared data from 3,007 births during a two-year period when the hospital did not have a central fetal monitoring system with data from 3,512 births two years earlier, when the system was operating. Comparing full-term and preterm deliveries in which central fetal monitoring was used with those in which it wasn't, they found no differences in the cesarean section rate, the proportion of admissions to the neonatal ICU, or the proportion of Apgar scores of less than 7.

"Hospitals buy these monitors and think they help with perinatal outcomes, but it simply is not true," says Matthew Withiam-Leitch, lead author of the report. He and his coauthors contend that although hospitals spend millions of dollars on central fetal monitoring systems, "the allocation of health care resources to these units may not be justified."

With central monitoring, nurses and physicians view a monitor usually located at a nursing station to track fetal status instead of visiting individual birthing rooms. Consequently, says Carol Sakala, director of programs at Childbirth Connection in New York City, central fetal monitoring "may fragment care, reduce bedside contact, compromise other types of direct assessment, isolate laboring women, and reduce valuable and appreciated supportive care during labor."

Another technology also does not live up to its promise. In 2000 the U.S. Food and Drug Administration approved use of the OxiFirst Fetal Oxygen Saturation Monitoring System as a complement to fetal heart rate monitoring. In cases of a nonreassuring fetal heart rate, which may indicate that the fetus is not receiving adequate oxygen during labor, the oxygen saturation monitor is supposed to help clinicians decide whether a cesarean section is indicated.

In a nationwide, randomized trial of 5,341 first-time mothers conducted by the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network between 2002 and 2005, fetal oxygen monitoring had no effect on the number of cesarean section deliveries or forceps- or vacuum-assisted vaginal deliveries. It also did not affect newborn outcomes.

The study's design called for the enrollment of 10,000 women, but recruiting was ended early because of the clear-cut results. "Pregnant women should not be exposed to a technology that appears to provide no benefit," said Steven Bloom, chairman of obstetrics and gynecology at the University of Texas Southwestern Medical Center in Dallas and lead author of the study.

Carol Potera