New medical technology tested at the Arizona Health Sciences Center that precisely measures the baby's oxygen levels may lessen the worry _ and perhaps reduce the frequency of Caesarian deliveries.

Oxygen deficiency in an unborn child can lead to brain damage, neurological disorders or even death, so caregivers take "non-reassuring" heart rate patterns seriously.

"If the electronic fetal monitor shows a worrisome heartbeat pattern, which is quite common, then we move quickly to emergency surgery. We have to be aggressive, even though the baby may actually not be in distress at all," explains Hugh Miller, MD, a UA perinatologist who specializes in high-risk births. "Now we finally have the technology to capture the actual oxygenation levels of the fetus throughout labor, and that eliminates all guessing."

The fetal oxygen monitor is a small sensor inserted into the uterus through the mother's cervix, then placed against the baby's cheek during labor. The sensor is attached to an external monitor, which gives continual readings of the baby's oxygen level. The UA was one of nine sites nationally where the sensors were tested; the device was approved by the Food and Drug Administration (FDA) in May.

In the nationwide clinical trials, Caesarian deliveries were reduced by 50 percent in cases of "non-reassuring" fetal heart beat when the oxygen monitor was used, says Dr. Miller, who led the UA study.

"In many cases when we used both electric fetal monitoring and the oxygen sensor, we found what looked to us like real distress was not _ the oxygen monitor showed the baby was getting plenty of oxygen and could be delivered normally with no problems," Dr. Miller says.

Hugh Miller, MD, holds up the probe that is part of the fetal oxygen monitor recently approved by the FDA.