Open AccessThe viscoelastic properties of the cervical mucus plug
Author(s) -
Bastholm Sara K.,
Becher Naja,
Stubbe Peter R.,
Chronakis Ioannis S.,
Uldbjerg Niels
Publication year - 2014
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.1111/aogs.12308
Subject(s) - viscoelasticity , rheometer , rheology , dynamic modulus , medicine , dynamic mechanical analysis , elastic modulus , composite material , population , materials science , polymer , environmental health
Objective To characterize the viscoelastic properties of cervical mucus plugs ( CMP s) shed during labor at term. Design Experimental research. Setting Department of Obstetrics and Gynecology, Aarhus University Hospital, Denmark. Population/Sample Spontaneously shed CMP s from 18 healthy women in active labor. Methods Viscoelastic properties of CMP s were investigated with a dynamic oscillatory rheometer using frequency and stress sweep experiments within the linear viscoelastic region. Main outcome measures The rheological variables obtained were as follows: elastic modulus ( G ′), viscous modulus ( G ″) and tan delta ( G ″/ G′ ). Random‐effects regression was used for statistical analysis. Results All CMP s showed solid‐like viscoelastic behavior. This was substantiated by the elastic modulus which was three to four times greater than the viscous modulus and by tan delta, which was <1 at all frequencies. Mean tan delta at 0.01 Hz was 0.38 (95% CI 0.34–0.43) and 0.27 (95% CI 0.23–0.32) at 1 Hz. The elastic modulus could be described by the relation G ′(ω) = Kω A [mean R 2 0.95 (95% CI 0.93–0.98)]. Despite relatively large variation in the rheological properties within CMP s, rheological variables obtained from frequency sweeps differed significantly among CMP s ( p < 0.05). Conclusion The CMP s are solid‐like viscoelastic structures. These rheological characteristics are probably essential for the CMP 's ability to form and sustain a plug in the cervical canal during pregnancy, thereby reducing the risk of ascending infections. The technique described here might be used for evaluation of an association between CMP viscoelasticity and preterm delivery.