title: Mechanical and structural changes of the rat cervix in late-stage pregnancy.
abstract: Dysregulated remodeling of the cervix precedes preterm birth, a major cause of infant mortality and morbidity. The goal of this work was to identify changes in the mechanical properties of the cervix in late gestation. The tensile and load relaxation properties of cervices from rats 15-21 days (full term) post-conception were measured. Stiffness and load at 25% circumferential strain decreased with gestational age and correlated with the initial circumference of the cervix. Load-relaxation curves were accurately described by a seven parameter quasi-linear viscoelastic model, where three parameters associated with stiffness and load capacity decrease with gestational age and correlate with initial circumference. Time-dependent parameters did not depend on age or structure. Mechanical properties correlated with water content, but unexpectedly not with measures of collagen content, solubility, or organization. Quantitative measurements of cervical stiffness and structure will lead to a more accurate description of cervical remodeling and prediction of preterm birth.
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, 1304 W Springfield Ave, Urbana, IL 61801, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Poellmann
authors.forename: Edward K
authors.initials: EK
authors.lastname: Chien
authors.forename: Barbara L
authors.initials: BL
authors.lastname: McFarlin
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Wagoner Johnson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002584:Cervix Uteri / Q000378:metabolism* / Q000502:physiology; D003094:Collagen / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005865:Gestational Age; D055595:Mechanical Phenomena; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013314:Stress, Mechanical; D013997:Time Factors; D014867:Water / Q000378:metabolism; D016474:Weight-Bearing
chemical_list: D014867:Water; D003094:Collagen