The pathophysiology of human premature cervical remodeling resulting in spontaneous preterm birth: Where are we now?

Approximately one in ten (approximately 500,000) pregnancies results in preterm birth (PTB) annually in the United States. Although we have seen a slight decrease in the U.S. PTB rate between 2007 and 2014, data from 2014 to 2015 shows the preterm birth rate has slightly increased. It is even more intriguing to note that the rate of PTB has not significantly decreased since the 1980s. In order to decrease the rate of spontaneous preterm birth (sPTB), it is imperative that we improve our understanding of normal and abnormal reproductive tissue structure and function and how these tissues interact with each other at a cellular and biochemical level. Since other chapters in this issue will be focusing on the myometrium and fetal membranes, the goal of this chapter is to focus on the compartment of the cervix. We will review the current literature on normal and abnormal human cervical tissue remodeling and identify gaps in knowledge. Our goal is also to introduce a revised paradigm of normal cervical tissue structure and function which will provide novel research opportunities that may ultimately lead to developing safe and effective interventions to significantly decrease the rate and complications of prematurity.