Peer Reviewed Scientific Papers
1. Can Myometrial Electrical Activity Identify Patients In Preterm Labor?
O. Most, O. Langer, R. Kerner, G. Ben David And I. Calderon
American Journal Of Obstetrics & Gynecology,199( 4): 378.E1-378.E6, Oct 2008
Measurement of myometrial electrical activity contributes an additional efficacious method for the early identification of patients in true spontaneous preterm labor.
Background and Objetive
The consequences of inconclusive diagnostic criteria and inaccurate early identification methods for premature labor include high admission and hospitalization rates for women with complaints of premature contractions, yet 50% deliver at term. The objectives of our study were to use noninvasive transabdominal electrical uterine myographic monitoring (EUM) as a predictor of preterm delivery and to compare the accuracy of EUM with that of fetal fibronectin (fFN) measurement and cervical length (CL). We hypothesized that false and spontaneous preterm labor can be differentiated by measuring myometrial electrical activity.
2. A Comparison Of Surface Acquired Uterine Electromyography And Intrauterine Pressure Catheter To Assess Uterine Activity
G. Haran, M. D. Fejgin And T. Biron-Shental
American Journal Of Obstetrics & Gynecology, 206(5):412. E1-5, May 2012
Intrauterine pressure catheter (IUPC) is the primary device used to evaluate uterine activity. In contrast to the IUPC, electrical uterine myography (EUM) enables noninvasive measurement of frequency, intensity, and tone of contractions. The aim of this study was to determine the accuracy of EUM compared to IUPC.
The correlation of the frequency, intensity, and tone of contractions between uterine electromyography and IUPC was strong with significant r values of 0.808-1
(P < .0001).
Electrical uterine electromyography yields information about uterine contractility comparable to that obtained with IUPC.
3. Uterine Electric Activity During The Third Stage Of Labor; A Look Into The Physiology Of A Deserted Stage
H. Rosen, L. Salzer, L. Hiersch, A. Aviram, A. Ben-Haroush and Y. Yogev
The Journal of Maternal Fetal Neonatal Medicine, 27(9):921-5, Jun 2014
To evaluate uterine activity during the third stage of labor and compare it to that observed in the second stage of labor.
The mean durations of the second and third stages were 51.9±63.5 and 15.4±7.5 minutes, respectively. During the third stage, uterine activity (contractions peaks) was similar to that observed during the second stage of labor (3.43±0.64 mWS versus 3.42±0.57 mWS, p = 0.8). No correlation was found between the duration of the third stage and EUM measurements during the third (p = 0.9) or the second (p = 0.2) stages of labor. No association was found between EUM measurements during the third stage and parity, maternal age, fetal weight, duration of labor, gestational age, gravity or BMI. The rate of oxytocin use during the second stage and EUM measurements during the second or third stage did not differ among women with short versus long duration of the third stage.
Uterine activity during the third stage is comparable and as intense as that occurring during the second stage. Third stage length cannot be predicted by contraction intensity during the second or third stage of labor.
4. Effect Of Prostaglandin E2 On Myometrial Electrical Activity In Women Undergoing Induction Of Labor
Aviram, N. Melamed, E. Hadar, O. Raban, L. Hiersch And Y. Yogev
American Journal Of Perinatology, 31(5):413-8, May 2014
To investigate the effect of prostaglandin E2 (PGE2) on electrical uterine activity using a novel uterine muscle electromyography device in patients undergoing induction of labor.
The EUM index was not increased significantly during the first 2 hours following PGE2 application (overall increase of 5.3±60.1%, p = 0.7). Peak EUM activity was observed during 2 to 8 hours following PGE2 application, which represented a statistically significant increase compared with the EUM index before PGE2 application (3.3±0.5 µJ vs. 2.5±0.95 µJ, p = 0.01), and with the EUM index 0 to 2 hours following PGE2 application (3.3±0.5 µJ vs. 2.3±0.9 µJ, p = 0.004).
The data suggests that in women undergoing labor induction with PGE2, uterine activity peaks 2 to 8 hours following PGE2 application. This information may provide more insight into the mechanism of PGE2 action.
5. Effect Of An Oxytocin Receptor Antagonist (Atosiban) On Uterine Electrical Activity
E. Hadar, N. Melamed, A. Aviram, O. Raban, L. Saltzer, L. Hiersch And Y. Yogev,
American Journal Of Obstetrics & Gynecology, 209(4):384. E1-7, Oct 2013
The purpose of this study was to investigate the effect of atosiban (Tractocile; Ferring, Limhamn, Sweden), an oxytocin receptor antagonist, on uterine electrical activity in women with preterm labor and to determine whether this information can assist in the prediction of preterm delivery.
Tractocile reduces uterine electrical activity in women with preterm labor. This information can provide more insight into the effects of tocolytic agents and to aid in the risk stratification of preterm delivery in women with preterm contractions.
6. Factors Affecting Uterine Electrical Activity During The Active Phase Of Labor Prior To Rupture Of Membranes
L. Hiersch, L. Salzer, A. Aviram, A. Ben-Haroush, E. Ashwal And Y. Yogev
The Journal of Maternal Fetal Neonatal Medicine, 1-4, Sep 2014. [Epub Ahead Of Print]
Limited data exist regarding uterine contraction intensity prior to membrane rupture. Using a novel technique of electrical uterine myography (EUM) we aimed to determine which factors affect myometrial activity during active phase of labor.
EUM was prospectively measured in 37 women with singleton pregnancy at term during the active phase of labor until membranes’ rupture. EUM was measured using noninvasive nine channels recorder with an EMG amplifier and three-dimensional position sensor. Uterine electrical activity was quantified with the EUM-index, defined as the mean electrical activity of the uterine muscle over a period of 10 min and measured in units of micro-Joule (microwatt per second [mW/s]).
The mean EUM-index at the first 10 min of the measurement was 3.3 ± 0.6 mW/s. In a stepwise linear regression model accounting potential confounders EUM was significantly affected by cervical dilatation (p = 0.005), maternal age (p = 0.04) and previous cesarean delivery status (p = 0.02). In a repeated measurement assessment of non-parametric Fridman’s test for all subjects who had at least 10 continuous EUM measurements, there was a significant increase in electrical uterine activity as labor progressed (p = 0.01). Conclusion: Electrical uterine activity during the active phase of labor prior to rupture of membranes is affected by maternal age, previous cesarean delivery status and cervical dilatation. Moreover, electrical uterine activity is enhanced throughout labor.
7. A Comparison Between Electrical Uterine Monitor, Tocodynamometer And Intra Uterine Pressure Catheter For Uterine Activity In Labor
E. Hadar, T. Biron-Shental, O. Gavish, O. Raban And Y. Yogev
The Journal of Maternal Fetal Neonatal Medicine, 1-8, Sep 2014 . [Epub Ahead of Print]
We aimed to evaluate the performance of a non-invasive EMG electrical uterine monitor (EUM) versus tocodynamometry (TOCO) by comparing both to internal uterine pressure catheter (IUPC).
Overall, 385 tracings from 43 women were analyzed. A similar rate of interpretable tracings between physicians was demonstrated for EUM (87%; 95% CI 80.9–92.7%) and IUPC (94.8%; 95% CI 83.4–96.3%), with a significantly lower rate for TOCO (67.5%; 95% CI 59.4–76.8%, p50.001). There is a significant difference in the contraction frequency for EUM versus IUPC (0.77 ± 2.3) compared to TOCO versus IUPC (-3.34 ± 4.97). There is a high variability between the timing of TOCO contractions as compared to IUPC (4.74 ± 10.03 seconds), while a gap of 8.46 ± 4.24 seconds was detected for EUM. The sensitivity, positive predictive value and false positive rate for individual contraction identification by TOCO and EUM are 54.0%, 84.4%, 15.6% and 94.2%, 87.6%, 12.4%, respectively.
EUM is efficient as IUPC for uterine activity assessment and both techniques are superior in comparison to external tocodynamometry. Our results support the use of non-invasive EMG technology to monitor uterine activity.