Electrohysterography during pregnancy: preliminary report
Gondry, J.; Marque, C.; Duchene, J.; Cabrol, D.
Biomedical Instrumentation and Technology 27(4): 318-324
1993
ISSN/ISBN: 0899-8205 PMID: 8369867 Document Number: 407262
Obstetrician-gynecologists used abdominal electrohysterography (EHG) to monitor uterine activity in 8 women admitted to the hospital in Amiens, France. The 1st group consisted of 3 women experiencing spontaneous contractions at 19-34 weeks gestation relating to preterm labor. The 2nd group were women undergoing induced abortion at 18-26 weeks gestation after intrauterine fetal death. Researchers wanted to test the feasibility of using EHG to detect uterine contractions. Physicians placed 1 Ag-AgC1 Beckman electrodes on the abdominal wall halfway between the uterine fundus and the symphysis on the medial vertical axis of the uterus and the ground electrode in a lateral position on the hip. An electrical burst correlated with 1 episode of mechanical activity in 215 (66.2%) of 325 uterine contractions. When the researchers excluded those cases with a full bladder or mechanical artifacts due to patient movement, this percentage rose to almost 89%. The temporal and spectral characteristics of the detected electrical bursts matched those from published reports. EHG was able to identify spontaneous contractions as early as 19 weeks gestation and induced contractions as early as 18 weeks gestation. The researchers still considered reliable detection of contractions during early pregnancy to be a problem, however. Regardless, they concluded that EHG is an appropriate way to monitor pregnancies at risk in a noninvasive fashion. They called for studies to determine the significance of the ENG signal in both normal and abnormal pregnancies. Perhaps, EHG can eventually be used as a home monitoring device to prevent preterm labor in women with a high risk pregnancy.