Cervical Changes Accompanying Birth

Investigations in the mouse have enhanced our understanding into the mechanisms of cervical remodeling and defined distinct pathways of ripening in term vs preterm birth. The cervix is a critical organ for maintenance of pregnancy and delivery of term fetus(es). Dynamic alterations in the structure and composition of the cervical extracellular matrix drive flexibility and mechanical strength of the cervix throughout pregnancy, labor, and the postpartum and are in part regulated by steroid hormones. This includes early pregnancy changes in collagen fibril processing and assembly that result in progressive modifications to collagen architecture and increased hyaluronan synthesis and deposition in late pregnancy with subsequent loss of tissue stiffness. Although once considered an acceleration of the normal physiological process, recent studies in antiprogestin- and infection-mediated premature cervical ripening models reveal distinct pathways of ripening as determined by differences in gene expression, immune cell populations, prostaglandin synthesis, hyaluronan expression, and collagen structure.