title: Second trimester cervical length and prolonged pregnancy (.).
abstract: OBJECTIVE
  To determine whether second trimester transvaginal ultrasound cervical length (CL) is associated with prolonged pregnancy (≥41 0/7 weeks) in nulliparous women who reach term (≥37 weeks) with a planned vaginal delivery.
  
  
  METHODS
  Retrospective cohort of nulliparous singletons 18 0/7-23 6/7 weeks gestation undergoing CL screening from 1/1/12 to 12/31/13. Women who delivered at term with spontaneous labor or reached 41 weeks were included. Primary outcome was incidence of prolonged pregnancy. Risk of prolonged pregnancy was assessed by CL quartile using odds ratio, adjusted for confounders (aOR) and a receiver operating characteristic (ROC) curve.
  
  
  RESULTS
  722 women were included, among them 171 (24%) had a prolonged pregnancy. There was a significant difference in BMI and race across CL quartiles. The aOR of having a prolonged pregnancy with CL in quartiles 2, 3, and 4 versus quartile 1 were 2.14(1.27-3.62), 2.72(1.59-4.65), and 1.69(1.02-3.03), respectively. CL ≥ 37 mm (beyond first quartile) was associated with a two-fold increased risk of prolonged pregnancy versus CL < 37 mm, (27% vs 15%, p < 0.01, aOR 2.17 (1.38-3.41)). ROC curve did not identify a CL cutoff that was predictive of prolonged pregnancy (AUC 0.544, p = 0.079).
  
  
  CONCLUSIONS
  Although a longer second trimester CL is associated with an increased risk for prolonged pregnancy, it is not predictive.
authors.affiliation: a Division of Maternal Fetal Medicine , Department of Obstetrics & Gynecology, Sidney Kimmel Medical College of Thomas Jefferson University , Philadelphia , PA , USA .
authors.forename: Rupsa C
authors.initials: RC
authors.lastname: Boelig
authors.affiliation: b Department of Maternal Fetal Medicine , Virginia Hospital Center , Arlington , VA , USA , and.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Orzechowski
authors.affiliation: c Department of Maternal Fetal Medicine , Baylor College of Medicine , Houston , TX , USA.
authors.forename: Anju
authors.initials: A
authors.lastname: Suhag
authors.affiliation: a Division of Maternal Fetal Medicine , Department of Obstetrics & Gynecology, Sidney Kimmel Medical College of Thomas Jefferson University , Philadelphia , PA , USA .
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Berghella
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D054791:Cervical Length Measurement / Q000379:methods*; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D016009:Chi-Square Distribution; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011273:Pregnancy, Prolonged; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult
keywords: Cervical length; late term pregnancy; post term pregnancy; prolonged pregnancy