title: The risk of impending preterm delivery in asymptomatic patients with a nonmeasurable cervical length in the second trimester.
abstract: OBJECTIVE
  The purpose of this study was to determine the pregnancy outcome of asymptomatic patients in the second trimester with a nonmeasurable cervical length (0 mm).
  
  
  METHODS
  This retrospective cohort study included 78 patients with singleton pregnancies and a sonographic nonmeasurable cervix that was detected at 14-28 weeks of gestation. Patients with cervical cerclage were excluded.
  
  
  RESULTS
  We found that (1) 75.3% of the patients delivered before 32 weeks of gestation; (2) the median diagnosis-to-delivery interval was 20.5 days, and the delivery rate within 7 and 14 days was 28.2% and 35.6%, respectively; and (3) patients with a nonmeasurable cervix that was diagnosed at <24 weeks of gestation had a shorter median diagnosis-to-delivery interval than patients who were diagnosed at 24-28 weeks of gestation (17.5 vs 41 days; P = .009).
  
  
  CONCLUSIONS
  Asymptomatic women with a nonmeasurable cervix in the second trimester have a median diagnosis-to-delivery interval of approximately 3 weeks. Almost 65% of these patients will not deliver within 2 weeks, yet 75% of them will deliver before 32 weeks of gestation. The earlier a nonmeasurable cervix is identified, the shorter the diagnosis-to-delivery interval.
authors.affiliation: Perinatology Research Branch, Intramural Division, National Institute of Child Health and Human Development/NIH/DHHS, Bethesda, MD 20892, USA.
authors.forename: Edi
authors.initials: E
authors.lastname: Vaisbuch
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Shali
authors.initials: S
authors.lastname: Mazaki-Tovi
authors.forename: Offer
authors.initials: O
authors.lastname: Erez
authors.forename: Juan Pedro
authors.initials: JP
authors.lastname: Kusanovic
authors.forename: Pooja
authors.initials: P
authors.lastname: Mittal
authors.forename: Francesca
authors.initials: F
authors.lastname: Gotsch
authors.forename: Clara
authors.initials: C
authors.lastname: Ward
authors.forename: Vivian
authors.initials: V
authors.lastname: Romero
authors.forename: Tinnakorn
authors.initials: T
authors.lastname: Chaiworapongsa
authors.forename: Percy
authors.initials: P
authors.lastname: Pacora
authors.forename: Lami
authors.initials: L
authors.lastname: Yeo
authors.forename: Sonia S
authors.initials: SS
authors.lastname: Hassan
mesh_terms: D000328:Adult; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D007752:Obstetric Labor, Premature; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal