Cervical elasticity during pregnancy: current state of the problem

Uterine cervix undergoes various changes throughout the pregnancy, which are characterized by the general term “remodeling”. In particular, this process includes changes of the length (shortening) and consistency (softening) of uterine cervix. The latter from the clinical point of view is important not only for observation of pregnant women with normal course of pregnancy but also for predicting such states as an outcome of labor induction or preterm delivery. Traditionally, cervical elasticity has been estimated through digital examination and Bishop score, however, currently there are available imaging techniques, which are more objective and precise. Amongst these methods, elastography plays a special role. Elastography allows measuring the capacity of tissues to deform. The softer the tissues, the higher mentioned capacity under the applied pressure. Currently there are various methods of elastography, starting from real-time elastography, when the capacity to be deformed is registered under the influence of physiologic movements or minimal manual pressure, to shear wave elastography, when the velocity of propagation of shear waves is measured. Although there are number of methods of elastography and perspectives of their use in obstetric practice, at the present time there is no consensus on standardization of these methods. In the cervical elastography this task is even more complicated, because there is no reference tissue to be compared with, especially this is true for strain elastography. The aim of this study was comparative analysis of methods estimating cervical elasticity and underlining current problems from the clinical point of view.