Fetal ECG Readings Offer No Advantage Over Heart Rate Monitoring During Labour
BETHESDA, Md -- August 13, 2015 -- A new technology that tracks the electrical activity of the fetal heart offers no advantages over conventional technology in preventing birth complications, according to a study published in the current issue of the New England Journal of Medicine.
The technology, referred to as fetal ST segment analysis, provides electrocardiogram (ECG) readings of a fetus's heart during the birth process. Traditionally, physicians have monitored only the fetal heart rate during labour.
The idea behind fetal ECG ST monitoring was that additional information about the heart would alert delivery room staff earlier than would heart rate monitoring alone, allowing them to intervene earlier to prevent potential complications.
For the study, more than 11,000 pregnant women were assigned to 1 of 2 groups when they went into labour after the 36th week of pregnancy. Physicians delivering women in the first, or open, group received readings from both the ECG ST monitors and fetal heart rate monitors. In the second, or masked, group, attending physicians saw only the fetal heart rate readings.
For each of the groups, the researchers recorded the occurrences of birth complications such as fetal and newborn death, seizures, the need for a ventilator after birth, high levels of acid in the blood, or an Apgar score of 3 or less. The occurrence of one or more of these complications was included in the primary outcome.
The researchers also tracked outcomes among the mothers, such as caesarean delivery, the use of forceps or vacuum to assist with vaginal delivery, infection of the membranes enclosing the amniotic fluid, and the need for a blood transfusion.
Adverse events occurred for 52 patients in the open arm and 40 in the masked arm -- a difference that was not statistically significant. Infants in the open group were slightly more likely to have an Apgar score of 3 or less (0.31%) than were those in the masked group (0.11%). Among the mothers, the researchers saw no differences in the frequency of any adverse events.
“Even though a new treatment or technology may appear promising, it really isn't possible to know whether it provides any benefits unless it's tested in a research study,” said Uma Reddy, MD, Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the National Institutes of Health (NIH), Bethesda, Maryland. “Our study didn't find any benefit for ECG ST monitoring in term births.”
SOURCE: National Institutes of Health