Direct Measurement of Human Cervical Tissue Permeability

The mechanical integrity of the uterine cervix is critical for the full-term success of a pregnancy. It must be strong to retain the fetus throughout gestation and then undergo a remodeling and softening process before labor to allow dilation and delivery. We hypothesize that the preterm birth (PTB) condition known as cervical insufficiency (CI) is related to a weak or soft cervix. Such PTBs are responsible for infant developmental problems and in severe cases, infant mortality. To understand the etiologies of CI, our overall research goal is to investigate the mechanical behavior of the cervix. As a foundation for future in-vivo tools to assess cervical softness, we aim to quantify cervical structure-material property relationships for nonpregnant (NP) and pregnant (PG) tissue from women with different obstetric backgrounds, including women with a previous history of CI. The goal of this study is to characterize cervical tissue as a poroelastic (biphasic) material. Here we present the results of two mechanical experiments on NP and PG hysterectomy cervical tissue samples: first, confined compression and second, direct measurement of permeability by a custom strain-adjustable permeation rig.