title: Is there a relationship between uterine activity and the length of the cervix in the second trimester?
abstract: OBJECTIVE
  The purpose of this study was to determine if a relationship could be detected between uterine activity and cervical change in the second trimester.
  
  
  METHODS
  Ten women with evidence of cervical change and 10 women with no cervical change (controls) were studied between 20 and 28 weeks gestation. Uterine activity was recorded using home uterine activity monitoring units. Cervical assessment was performed using transvaginal ultrasound.
  
  
  RESULTS
  There was no statistically significant difference in the contractions per hour in the cervical change group (1.26 +/- 0.38; mean +/- SEM) compared to the controls (1.13 +/- 0.48) (p 0.48; Mann-Whitney U test). There were significant differences in closed endocervical length (p < 0.001) and internal os dilatation (p 0.004), the cervical change group demonstrating a shorter closed endocervical length and greater internal os dilatation.
  
  
  CONCLUSIONS
  This preliminary study shows no evidence of a relationship between uterine activity and endocervical canal length in the second trimester.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Sydney at The Nepean Hospital, Penrith, NSW, Australia.
authors.forename: C M
authors.initials: CM
authors.lastname: Cook
authors.forename: D A
authors.initials: DA
authors.lastname: Ellwood
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D020070:Cervical Ripening / Q000502:physiology; D002584:Cervix Uteri / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D018670:Monitoring, Ambulatory; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014463:Ultrasonography; D014590:Uterine Contraction / Q000502:physiology*