Finding blips in use of fetal heart monitors

For about 20 years, doctors have routinely checked a baby’s heartbeat with an electronic monitor as the mother goes into labor. But an old-fashioned stethoscope might work just as well.

The practice of tracking the baby’s heartbeat for the first 20 minutes after admission to the hospital, called admission cardiotocography, has been used to determine which babies might need more invasive electronic monitoring during delivery. The idea has been to identify those babies who might be at risk of oxygen deprivation, which has been associated with cerebral palsy and other neurological disorders.

But a new study found that the early high-tech heart monitoring doesn’t improve a baby’s chances for a healthy birth.

“A widespread and expensive practice is largely unjustified,” said Lawrence Impey, lead author of the study. “By concentrating our attention on the pattern of the baby’s heartbeat in labor, we are seeing only a fraction of the causes of stillbirth and handicap. We need better research to understand the processes behind these.”

Impey and his colleagues at the National Maternity Hospital in Dublin, Ireland, randomly assigned about 8,500 women to either have their babies electronically monitored or periodically checked with a stethoscope soon after admission. They found the rate of deaths and moderate-to-severe illnesses among the babies was the same in both groups -- about 1.3%.

Their results appear in this week’s issue of The Lancet.

In an accompanying commentary, Stephen B. Thacker and Donna F. Stroup, epidemiologists with the federal Centers for Disease Control and Prevention in Atlanta, said that widespread use of the early electronic monitoring should be discouraged until more studies can examine its safety -- because it sometimes leads to more invasive and risky monitoring -- and effectiveness among those babies who might benefit from it.

Dr. Fredric Frigloletto, chief of obstetrics and gynecology at Massachusetts General Hospital in Boston, said he would have been surprised if the study had found much benefit in heartbeat monitors.

Because the testing provides a printout of the baby’s heartbeat, called a 20-minute strip, Frigloletto said, the test became part of the practice of defensive medicine.