title: Sonographic myometrial thickness predicts the latency interval of women with preterm premature rupture of the membranes and oligohydramnios.
abstract: OBJECTIVE
  Term labor is associated with global thinning of the myometrium. We hypothesized that a thickened myometrium at the time of preterm premature rupture of membranes (PPROM) predicts less myometrial wall stress and, consequently, a longer latency interval.
  
  
  METHODS
  Myometrial thickness was measured prospectively in 76 pregnant women enrolled in the following groups: PPROM (n=28, mean [range], gestational age [GA]: 29.5 weeks [w] [21.0 w-33.0 w]), preterm nonlabor control group (P-CTR), (n=21, GA: 27.5 w [23.0 w-32.0 w]) and term nonlabor control (T-CTR) (n=27, GA: 38.6 w [37.0 w-41.6 w]). All PPROM women had oligohydramnios (AFI: 1.4 cm [0.0 cm-5.1 cm]). MT was measured ultrasonographically at the midanterior, fundal, posterior, and lower uterine segment wall in cases and controls with an intraoperator variability <10%.
  
  
  RESULTS
  Women in the PPROM group displayed uniform thickness of the uterine body (mean +/- SEM, anterior: 10.6 +/- 0.6 mm, fundal: 10.7 +/- 0.7 mm, posterior: 8.9 +/- 0.5 mm, P=.078). At midanterior site the myometrium of the PPROM group was thicker compared to both P-CTR (P < .001) and T-CTR (P=.025) groups. This difference was preserved at the fundus (PPROM vs P-CTR, P < .001; PPROM vs T-CTR, P=.015). There was a positive correlation between fundal MT and latency period (r=0.43, P=0.02) that persisted after adjusting for GA (P=.04). A fundal MT less than 12.1 mm was 93.7% sensitive and 63.6% specific for the identification of women whose latency period was less than 120 hours.
  
  
  CONCLUSIONS
  Significant thickening of the anterior and fundal walls of the uterus follows PPROM. A thick myometrium in nonlaboring patients with PPROM is associated with longer latency interval. Sonographic evaluation of MT may represent an alternative clinical tool for the prediction of a short latency interval in women with PPROM.
authors.affiliation: Yale University, New Haven, CT, USA. catalin.buhimschi@yale.edu
authors.forename: Catalin S
authors.initials: CS
authors.lastname: Buhimschi
authors.forename: Irina A
authors.initials: IA
authors.lastname: Buhimschi
authors.forename: Errol R
authors.initials: ER
authors.lastname: Norwitz
authors.forename: Anna K
authors.initials: AK
authors.lastname: Sfakianaki
authors.forename: Benjamin
authors.initials: B
authors.lastname: Hamar
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Copel
authors.forename: George R
authors.initials: GR
authors.lastname: Saade
authors.forename: Carl P
authors.initials: CP
authors.lastname: Weiner
mesh_terms: D000328:Adult; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D009215:Myometrium / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012680:Sensitivity and Specificity; D014463:Ultrasonography