. Author manuscript; available in PMC: 2012 Mar 1.

Published in final edited form as: Am J Obstet Gynecol. 2010 Dec 8;204(3):228.e1–228.10. doi: 10.1016/j.ajog.2010.09.024

Table 2.

Comparison of Diagnostic EMG Parameters for Preterm Delivery Within, as Compared to After, 7 Days from the Uterine Electromyography Measurement

EMG Parameter	Women Delivering Within 7 days	Women Delivering After 7 days	P-value
PS Peak Frequency *	0.56 ± 0.15 Hz	0.44 ± 0.07 Hz	0.002
Propagation Velocity *	52.56 ± 33.94 cm/s	11.11 ± 5.13 cm/s	<0.001
PS Median Frequency	0.64 ± 0.12 Hz	0.68 ± 0.05 Hz	0.11
PS Peak Amplitude	50.98 ± 84.70 μV²	70.56 ± 134.64 μV²	0.63
PS Median Amplitude	16.27 ± 44.14 μV²	10.16 ± 16.29 μV²	0.58
Mean Burst Duration	35.53 ± 9.00 s	39.32 ± 12.26 s	0.21
SD of Burst Duration	7.44 ± 5.85 s	10.16 ± 7.0 s	0.07
Mean Inter-burst Interval	307.5 ± 178.38 s	348.96 ± 227.27 s	0.65
SD of Inter-burst Interval	184.14 ± 136.68 s	149.76 ± 157.92 s	0.26

PS power spectrum; SD standard deviation; P value calculated by Mann-Whitney U-test and Student’s T-test.* represents statistical significance (P<0.05).