A large government study has concluded that monitoring fetal oxygen levels during labor does not lead to healthier newborns or reduce unnecessary cesarean deliveries.
Fetal monitoring has long been controversial. Since the 1970s, doctors have routinely listened to fetal heartbeats despite no real evidence it did any good. In fact, some research found that it increased the number of C-sections by making doctors nervously reach for a scalpel whenever the monitor showed an abnormal blip.
New technology that measures oxygen levels in the blood of a fetus was thought to offer a better way to tell which babies were truly at risk. In 2000, the Food and Drug Administration conditionally approved one such device but required further study before allowing it into general use.
The study, published in today’s New England Journal of Medicine, was the biggest to date, involving more than 5,000 women, and was meant to be the definitive word. It was halted early because of overwhelming evidence that the technology was ineffective.
“There’s no reason to use it,” said Dr. Steven Bloom, the study’s lead author and chief of obstetrics and gynecology at the University of Texas Southwestern Medical Center. “We didn’t find any evidence of harm, but why should we invest valuable health-care dollars in something that doesn’t have a proven benefit?”
In an accompanying editorial, Dr. Michael Greene of Massachusetts General Hospital, who had no role in the research, noted that for once, an expensive technology can be stopped before it finds its way into widespread use. Fetal oxygen monitors are not part of routine care.
“This genie has not yet escaped from the bottle,” he wrote.
In fact, Pleasanton, Calif.- based Nellcor, which received FDA approval to market its OxiFirst devices, stopped selling them this year because of a lack of demand, said company spokeswoman Kristin Garvin.
