Comparing uterine electromyography activity of antepartum patients versus term labor patients.

OBJECTIVE The purpose of this study was to compare uterine electromyography of patients delivering>24 hours from measurement with laboring patients<or=24 hours from measurement. STUDY DESIGN Fifty patients (group 1: labor, n=24; group 2: antepartum, n=26) were monitored using transabdominal electrodes. Group 2 was recorded at several gestations. Uterine electrical "bursts" were analyzed by power-spectrum from 0.34 to 1.00 Hz. Average power density spectrum (PDS) peak frequency for each patient was plotted against gestational age, and compared between group 1 and group 2. Frequency was partitioned into 6 bins, and associated burst histograms compared. RESULTS Group 1 was significantly higher than group 2 for gestational age (39.87+/-1.08 vs 32.96+/-4.26 weeks) and average PDS peak frequency (0.51+/-0.10 vs 0.40+/-.03 Hz). Histograms were significantly different. A correlation coefficient of .41, with significance, was found with PDS vs gestation. CONCLUSION Uterine electromyography in antepartum patients is significantly lower than in laboring patients delivering<or=24 hours from measurement.

[1]  M Macklin,et al.  Changes in the conduction of the fetal electrocardiogram to the maternal abdominal surface during gestation. , 1977, American journal of obstetrics and gynecology.

[2]  C Marque,et al.  Uterine electromyography: a critical review. , 1993, American journal of obstetrics and gynecology.

[3]  G. Saade,et al.  Control and assessment of the uterus and cervix during pregnancy and labour. , 1998, Human reproduction update.

[4]  J D Wilson,et al.  Analysis of uterine contractions: a dynamical approach , 2003, The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians.

[5]  M C Carter,et al.  FETAL HEART RATE MONITORING USING THE ABDOMINAL FETAL ELECTROCARDIOGRAM , 1980, British journal of obstetrics and gynaecology.

[6]  R. Scott,et al.  The short-time Fourier transform and muscle fatigue assessment in dynamic contractions. , 2001, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[7]  P. Nathanielsz,et al.  Electromyographic activity of the nonpregnant and pregnant sheep uterus. , 1982, American journal of obstetrics and gynecology.

[8]  G. Wolfs,et al.  Electromyographic Observations on the Human Uterus during Labour , 1979, Acta obstetricia et gynecologica Scandinavica. Supplement.

[9]  G. Saade,et al.  Uterine activity during pregnancy and labor assessed by simultaneous recordings from the myometrium and abdominal surface in the rat. , 1998, American journal of obstetrics and gynecology.

[10]  R. Garfield,et al.  Electrical Activity of the Human Uterus During Pregnancy as Recorded from the Abdominal Surface , 1997, Obstetrics and gynecology.

[11]  P. Nathanielsz,et al.  Alteration of 24-hour rhythms in myometrial activity in the chronically catheterized pregnant rhesus monkey after a 6-hour shift in the light-dark cycle. , 1990, American journal of obstetrics and gynecology.

[12]  G. Saade,et al.  Predicting Term and Preterm Delivery With Transabdominal Uterine Electromyography , 2003, Obstetrics and gynecology.

[13]  K D Burau,et al.  Diurnal and Gestational Patterns of Uterine Activity in Normal Human Pregnancy , 1994, Obstetrics and gynecology.

[14]  S N Reddy,et al.  Frequency analysis of gut EMG. , 1987, Critical reviews in biomedical engineering.

[15]  H KURIYAMA,et al.  A study of the parturient uterus with the microelectrode technique. , 1961, Endocrinology.

[16]  Catherine Marque,et al.  Uterine EHG Processing for Obstetrical Monitorng , 1986, IEEE Transactions on Biomedical Engineering.

[17]  R. Garfield,et al.  Myometrial electrophysiologic activity and gap junctions in the pregnant rabbit. , 1984, American journal of obstetrics and gynecology.

[18]  G. Saade,et al.  Instrumentation for the diagnosis of term and preterm labour , 1998, Journal of perinatal medicine.

[19]  T. Noakes,et al.  Effects of supramaximal exercise on the electromyographic signal , 2003, British journal of sports medicine.

[20]  P. Nathanielsz,et al.  Primate parturition and the role of the maternal circadian system. , 1994, European journal of obstetrics, gynecology, and reproductive biology.

[21]  O. P. O'Brien,et al.  Action of an estrogen antagonist on the electrical and mechanical properties of the rat uterus in vitro. , 1967, Endocrinology.

[22]  D. Kumar,et al.  Studies in human myometrium during pregnancy , 1961 .

[23]  J. P. Morucci,et al.  External recording and processing of fast electrical activity of the uterus in human parturition , 1984, Medical and Biological Engineering and Computing.