The Biomechanics of Pregnancy

Preterm birth is a public health problem affecting almost 15 million newborns each year, with almost one million cases annually being fatal. Despite many decades of research, identifying high-risk pregnancies remains difficult. Even with the therapies currently available to clinicians, 95% of preterm births are seemingly intractable. We see a great opportunity for engineers to collaborate with clinicians to help reduce the adverse health impact of this phenomenon. This work is a multi-faceted contribution to the study of the biomechanical problem of preterm birth. We portray the successful, full-term, pregnancy as a delicate balance of organ geometry, tissue deformation behavior, and the physical interaction between the uterus, cervix, and fetal membranes. The cervix is our focus, as its preterm ripening and dilation are the final pathway to premature delivery. We consider a selection of geometric and material factors, studying their impact on the loading that occurs in the cervix. We also study the mechanical implications of the use of a cervical pessary on the mechanical environment of pregnancy. Our mechanical analyses use a custom parameterized model of the pregnant anatomy, coupled with Finite Element Analysis techniques, to allow for rapid model development. In addition, we present a push towards the in-vivo measurement of cervical material properties by way of a phantom study using modern MRI techniques.