In one of the largest and most rigorous studies to date, Washington University School of Medicine researchers are trying to better understand the use of the most common obstetric procedure — electronic fetal monitoring.

Electronic fetal monitoring was introduced in the early 1970s to continuously monitor babies' heart rates and surgically intervene if necessary. The goal was to reduce the risk of cerebral palsy and death resulting from insufficient oxygen to the fetal brain.

Despite the monitoring being used in over 85 percent of U.S. births, the stillbirth rate has not changed and the rate of cerebral palsy has increased.

"The technology became accepted practice before we knew if it worked or not," said Dr. Alison Cahill, assistant professor of obstetrics and gynecology at Washington University School of Medicine.

Cahill and her colleagues have received a five-year, $3.5 million grant from the National Institute of Child Health and Human Development to compare the fetal heart rate patterns to neonatal outcomes in 7,000 deliveries.

For decades, the patterns were divided into two categories: reassuring and nonreassuring. New recommendations released two years ago divided the patterns into three categories considered normal, intermediate and abnormal. Intermediate readings are the most common, Cahill said, yet "we have no information about the meanings of those patterns."

Scientists hope the study will result in more accurate interpretations of the recordings and also help reduce the rate of Caesarean sections, which have risen to 32 percent of all births from 7 percent when electronic fetal monitoring was introduced.

"Physicians are intervening on EFM recordings they think have particular meaning, but the recordings are not accurately predicting which babies will have neurological damage," Cahill said. "If we can learn more about these recordings and what they mean, we can possibly reduce the number of c-sections and also improve newborn care."

Because of the threat of liability, many babies who might have been fine after a vaginal delivery are being delivered surgically or with forceps, said Dr. George Macones, head of the university's department of obstetrics and gynecology.

In the study, researchers will assess the electronic fetal monitoring recordings 120 minutes before delivery and see if the recordings predict which newborns will suffer brain damage. In addition, 200 full-term babies delivered at Barnes-Jewish Hospital will undergo more detailed tests to detect neurological damage, such as a cord blood sample and MRI.

Electronic fetal monitoring technology holds promise, Cahill said. "It's hard to imagine second-to-second monitoring is less valuable. We just haven't looked at it in a successful way."