Document Detail

Active contractions of the cervix in the latent phase of labour.
MedLine Citation:
PMID:  10430195     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: To study the activity of the human uterine cervix at the onset of labour and further characterise cervical asynchronous electromyographic (EMG) activity in the latent phase. DESIGN: Prospective observational study. SETTING AND PARTICIPANTS: Clinical hospital in Ljubljana. PARTICIPANTS: Forty-seven healthy nulliparous women with relatively unripe cervices requiring induction of labour. METHODS: Simultaneous registration of a cervical EMG and of the intrauterine pressure at the very early stage of labour; subsequent EMG signal processing to determine its time, amplitude and frequency parameters. MAIN OUTCOME MEASURES: Simultaneous comparison of the cervical EMG and the mechanical activity of the uterine corpus to deduce electrical properties of the cervical smooth muscle tissue and its activity. RESULTS: EMG bursts, asynchronous with the contractions of the uterine corpus, were registered in 20 out of 47 women. In 14 women bursts appeared independent of uterine corpus contractions and in six they followed the peak of contractions. The bursts had low average median frequency (0.3 Hz). In seven women bursts were superimposed onto a background EMG (median frequency = 1.2 Hz). CONCLUSIONS: Bursts in the cervical EMG may appear asynchronously with the uterine contractions. Bursts not related to contractions suggest active and independent cervical muscle activity. The bursts which follow contractions may be an active response of the cervical musculature to passive stretching during a contraction. The EMG frequency content suggests two different contraction mechanisms or a different origin of the EMG in the cervix.
D Rudel; M Pajntar
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  British journal of obstetrics and gynaecology     Volume:  106     ISSN:  0306-5456     ISO Abbreviation:  Br J Obstet Gynaecol     Publication Date:  1999 May 
Date Detail:
Created Date:  1999-09-02     Completed Date:  1999-09-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7503752     Medline TA:  Br J Obstet Gynaecol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  446-52     Citation Subset:  AIM; IM    
Department of Obstetrics and Gynaecology, Medical Centre Ljubljana, Slovenia.
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MeSH Terms
Amnion / surgery
Cervical Ripening
Labor Onset / physiology*
Labor, Induced
Prospective Studies
Time Factors
Uterine Contraction / physiology*

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