Pathophysiology
Clinical meaning
At the NP level, managing cervical insufficiency requires understanding the evidence-based criteria for cerclage versus progesterone therapy. Cervical remodeling in insufficiency involves premature activation of matrix metalloproteinases (MMP-1, MMP-8) that degrade collagen, combined with increased hyaluronic acid and decreased proteoglycan content in the cervical stroma. Progesterone maintains cervical rigidity by suppressing MMP expression and maintaining the collagen-rich extracellular matrix. The OPPTIMUM trial showed vaginal progesterone reduced preterm birth in women with short cervix (<25 mm); the Berghella meta-analysis confirmed that cerclage reduces preterm birth in singleton pregnancies with short cervix AND prior preterm birth. The decision algorithm stratifies by history (prior preterm birth), cervical length, and number of fetuses to select progesterone, cerclage, or both.