Home Fetal Heartbeat Monitors May Deceive, Doctors Warn

Nov. 7, 2009— -- Expectant mothers may enjoy listening to their unborn babies' heartbeats, but they shouldn't rely on home fetal heart monitors to provide an accurate picture of fetal health, researchers say.

The devices may provide false reassurance in some situations, according to Dr. Abhijoy Chakladar of Princess Royal Hospital in West Sussex, England.

In the British Medical Journal, Chakladar reported a case in which a 34-year-old woman who was 38 weeks pregnant went to the emergency department because she couldn't hear her baby's heartbeat with her home fetal heart monitor.

A few days earlier, she said she had noticed that the baby was moving far less than usual. However, she reassured herself that everything was OK by listening to the monitor. A couple of days later, when she listened again, she couldn't detect anything and sought medical help.

Physicians performed an ultrasound and found no fetal heart activity. They gave the diagnosis -- intrauterine death -- but could not explain why it had happened.

All blood tests and infection screens were normal. There was no significant microbial growth from the placenta or fetus, and the fetus seemed morphologically normal, Chakladar said.

He said the stillbirth "may have been unavoidable," but listening to the fetal heart monitor "certainly delayed presentation to the hospital."

"Without training," he added, sounds heard on the monitor "could easily be misinterpreted." Likely, the mother had simply heard her own pulse or placental flow instead.

Chakladar said the risks of having a mother delay seeking medical attention -- as well as the limitations of some of the devices -- tend to be overlooked.

Home monitoring devices can give only a snapshot of the heart rate and "provide no indication of other important prognostic features," he said.

Medical professionals provide context that an untrained mother can't, he added. For example, midwives and obstetricians take careful histories and make experienced observations before making interpretations for a diagnosis.