New technology for measuring blood oxygen levels of a baby during labor which was intended to provide information useful for preventing birth complications, apparently offers no apparent benefit.
Researchers from the National Institutes of Health research network say the technology, known as fetal oxygen saturation monitoring, was designed for use along with electronic fetal monitoring, which tracks the fetal heart rate, to measure changes in fetal oxygen levels.
The designers hoped that knowing the oxygen status of the baby during labour would provide information on the health of the baby, especially when there were disturbances in the fetal heart rate during labour.
The study was conducted by researchers in the The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, who say the technology offered no apparent advantage in interpreting the meaning of abnormal fetal heart rates and was halted early because of overwhelming evidence that the technology was ineffective.
The study's first author Dr. Steven L. Bloom, chief of obstetrics and gynecology at the University of Texas Southwestern Medical Center in Dallas, says they could find no reason to use the technology.
For the study, doctors monitored the fetal oxygen levels in 5,341 women pregnant for the first time at 14 university hospitals in the United States.
As soon as the mother's waters broke, a sensor was inserted into the uterus and placed against the fetus' temple or cheek.
The sensor then provided an up-to-the-minute reading of the fetus' oxygen levels.
The women were then randomly separated into two groups; in one group, doctors could read the oxygen levels, while the information was hidden to the other group.
In both groups, about 26 percent of deliveries were done by C-section and no difference between the two groups was found regarding stillbirths, infections or other newborn problems.
Dr. Catherine Spong, M.D., a co-author of the study and chief of NICHD's Pregnancy and Perinatology Branch, says abnormal oxygen readings were common among babies showing abnormal heart rates but they were also common among babies with normal heart rates.