Cervical Softening, Effacement, and Dilatation

Abstract

The rearrangement of the extracellular matrix of the uterine cervix during pregnancy and parturition occurs by the progression of a complex, finely regulated biochemical cascade. In the past decade, major advances in our understanding of these molecular and biochemical changes have been made, yet the complete metabolic cascade is not understood. In this paper, current information regarding these metabolic pathways is reviewed and areas for further research are discussed.

Term labor and preterm labor are etiologically heterogenous. The triggering mechanisms of the biochemical rearrangement of collagen, proteoglycans, and elastic fibers are likely different, however, depending on the presenting clinical situation. While the pathways of extracellular matrix rearrangement may be similar, studies focusing on term labor do not provide complete information regarding preterm labor. Animal models and in vitro studies are extremely useful, but do not in themselves explain the entire story of cervical softening, dilatation, and effacement. Inflammatory cells play a role in this process but the exact nature of their involvement is unclear. Until the complete metabolic cascade is known, little progress in our ability to logically control the incidence of preterm, dysfunctional, and postterm labor can be achieved.

Key Words:

• Uterine cervix
• Parturition
• Pregnancy
• Extracellular matrix
• Collagen
• Elastin
• Collagenase