Archives of Gynecology and Obstetrics

, Volume 285, Issue 1, pp 31–35 | Cite as

Raised electrical uterine activity and shortened cervical length could predict preterm delivery in a low-risk population

  • Ozren Grgic
  • Ratko Matijevic
  • Krunoslav Kuna
Materno-Fetal Medicine



To compare diagnostic accuracy of sonographic cervical length (CL) measurement and uterine electric activity assessed by electromyography (EMG) in second trimester regarding prediction of preterm delivery (PTD).


Prospective study of 308 low-risk women. Shortened CL was defined as ≤25 mm (≤5th centile), while raised EMG activity was defined as the presence of ≥20 action potentials in 20 min of assessment (≥95th centile). Outcome measures were diagnostic accuracy of both tests alone or in combination for prediction of PTD and early PTD (≤34 weeks).


The incidence of PTD was 23/308 (7.4%) while the incidence of early PTD was 9/308 (2.9%). Shortened CL and raised EMG activity were significantly related to PTD [prevalence-weighted likelihood ratio (pw-LR) 1.9, 95% CI 1.0–3.5 vs. 9.5, 95% CI 2.5–35.7], but not to early PTD (pw-LR 0.4, 95% CI 0.2–0.8 vs. 0.6, 95% CI 0.3–1.7). Significant predictive value for early PTD was found only if both tests were combined (pw-LR 4, 95% CI 1.3–14.3).


Shortened CL and raised EMG activity in second trimester have significant diagnostic accuracy regarding prediction of PTD in a low-risk population. However, in order to be useful as a predictor for early PTD both tests must be positive.


Cervical length Low-risk population Second trimester Preterm delivery Transvaginal ultrasound Uterine electromyographic activity 



This study was funded by the Croatian Ministry of Science, Education, and Sport as Project No. 108-0000000-0378.

Conflict of interest



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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.University Department of Obstetrics and GynecologyUniversity Hospital Sestre MilosrdniceZagrebCroatia
  2. 2.University Department of Obstetrics and GynecologySchool of Medicine, Sveti Duh HospitalZagrebCroatia

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