title: Short fetal leukocyte telomere length and preterm prelabor rupture of the membranes.
abstract: BACKGROUND
  Rupture of the fetal membranes is a common harbinger of imminent labor and delivery. Telomere shortening is a surrogate for oxidative stress (OS) and senescence. Fetal leukocyte and placental membrane DNA telomere lengths were evaluated to determine their association with preterm prelabor rupture of the membranes (pPROM) or spontaneous preterm births with intact membranes (PTB), compared to term birth.
  
  
  METHODS
  Telomere lengths were quantified in cord blood leukocytes (n = 133) from three major groups: 1) pPROM (n = 28), 2) PTB (n = 69) and 3) uncomplicated full term births (controls, n = 35), using real-time quantitative PCR. Placental membrane specimens (n = 18) were used to correlate fetal leukocyte and placental telomere lengths. Telomere length differences among the groups were analyzed by ANOVA. Pearson correlation coefficients determined relationships between leukocyte and placental membrane telomere lengths.
  
  
  RESULTS
  In pregnancies with intact membranes, fetal leukocyte telomere length was inversely proportional to gestational age. The mean telomere length decreased as gestation progressed, with the shortest at term. pPROM had telomere lengths (9962 ± 3124 bp) that were significantly shorter than gestational age-matched PTB (11546 ± 4348 bp, p = 0.04), but comparable to term births (9011 ± 2497 bp, p = 0.31). Secondary analyses revealed no effects of race (African American vs. Caucasian) or intraamniotic infection on telomere length. A strong Pearson's correlation was noted between fetal leukocyte and placental membrane telomere lengths (ρ = 0.77; p<0.01).
  
  
  CONCLUSIONS
  Fetal leukocyte telomere length is reduced in pPROM compared to PTB but is similar to term births. pPROM represents a placental membrane disease likely mediated by OS-induced senescence.
authors.affiliation: Division of Maternal-Fetal Medicine and Perinatal Research, Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America. ram.menon@utmb.edu
authors.forename: Ramkumar
authors.initials: R
authors.lastname: Menon
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.forename: Patrice
authors.initials: P
authors.lastname: Basanta-Henry
authors.forename: Lina
authors.initials: L
authors.lastname: Brou
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Berga
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Fortunato
authors.forename: Robert N
authors.initials: RN
authors.lastname: Taylor
mesh_terms: D005260:Female; D005312:Fetal Blood; D005322:Premature Rupture of Fetal Membranes / Q000209:etiology / Q000473:pathology*; D005865:Gestational Age; D006801:Humans; D007962:Leukocytes / Q000648:ultrastructure*; D018384:Oxidative Stress; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D047928:Premature Birth; D016615:Telomere / Q000648:ultrastructure*