Biomechanical Modeling of Cervical Tissue: A Quantitative Investigation of Cervical Incompetence

We introduce a phenomenological fully three-dimensional constitutive model for the large strain, time dependent mechanical behavior of cervical tissue. The proposed model captures specific aspects of the complex biomechanical response of cervical stroma and is able to account of for the contributions of each constituent and for the cooperative nature of the tissue response. We rely on in vitro mechanical tests to determine representative constitutive parameters for normal (non-pregnant) tissue before it undergoes the maturation process. These parameters are then altered to mimic the effects of the modified biochemical equilibrium associated with a condition of cervical incompetence. The constitutive model is integrated with pelvic anatomy to obtain a finite element model of the cervix in pregnancy. The effects of the altered tissue properties on the ability of the cervix to maintain the pregnancy are investigated.