title: Role of 3-dimensional power Doppler sonography in differentiating pregnant women with threatened preterm labor from those with an asymptomatic short cervix.
abstract: OBJECTIVE
  To compare cervical volumes and vascularization indices using 3-dimensional power Doppler sonography among singleton pregnancies with threatened preterm labor and an asymptomatic short cervix.
  
  
  METHODS
  Three hundred asymptomatic healthy pregnant women between 24 and 34.6 gestational weeks were prospectively scanned for cervical length. If cervical length was short, defined as below the 10th percentile for gestational age, the cervical volume and vascularization indices (vascularization index [VI], vascularization-flow index [VFI], and flow index [FI]) were measured. Women receiving any treatment for preterm delivery prevention were excluded. During this period, the same sonographic parameters were measured among patients with threatened preterm labor admitted to our institution during the first 24 hours after admission. Multiple pregnancies and fetal or maternal pathologic conditions, were exclusion criteria. Data on body mass index, maternal age, smoking, parity, family history of preterm birth, mother who was born preterm, and previous preterm birth among the pregnant women were recorded. Sonographic and medical history parameters were compared between the two groups.
  
  
  RESULTS
  Twenty-nine asymptomatic healthy women (9.6%) had a short cervix. Additionally, 71 pregnancies with threatened preterm labor were scanned. There were no statistically significant differences between the groups in medical history parameters or cervical length. The cervical volume was smaller in threatened preterm cases (12.90 versus 17.168 cm(3); P = .005). The VI and VFI were lower in women with an asymptomatic short cervix (VI, 4.369% versus 15.939%; P < .001; VFI, 1.514 versus 4.878; P < .001). The FI was higher in the short cervix group (33.581 versus 30.311; P = .006).
  
  
  CONCLUSIONS
  Three-dimensional transvaginal sonography reveals differences in cervical volume and vascularization indices between pregnancies with an asymptomatic short cervix and cases with threatened preterm labor, although cervical length is similar in both groups.
authors.affiliation: Department of Obstetrics and Gynecology, Sant Joan de Déu Hospital, Passeig Sant Joan de Déu 2, 08950 Esplugues, Barcelona, Spain. rdediego@hsjdbcn.org.
authors.forename: Raül
authors.initials: R
authors.lastname: De Diego
authors.forename: Joan
authors.initials: J
authors.lastname: Sabrià
authors.forename: Antonio
authors.initials: A
authors.lastname: Vela
authors.forename: David
authors.initials: D
authors.lastname: Rodríguez
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: Gómez
mesh_terms: D000328:Adult; D000465:Algorithms; D054791:Cervical Length Measurement / Q000379:methods*; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult
keywords: 3-dimensional Doppler sonography; obstetric ultrasound; vascular indices; virtual organ computer-aided analysis