Matrix metalloproteinases and their tissue inhibitors in preterm perinatal complications.

The objective of this article is to review the role of matrix metalloproteinases (MMPs) in fetomaternal/neonatal complications of preterm birth. The function of MMPs as proteolytic enzymes involved in tissue remodeling/destruction is reviewed in preterm labor, preeclampsia, premature rupture of membranes, intrauterine growth restriction, chronic lung disease, necrotizing enterocolitis, intraventricular hemorrhage, cystic periventricular leukomalacia, and retinopathy of prematurity. Cytokines, steroid hormones, and reactive oxygen species all regulate MMP labor and expression/activity. In labor, activation follows an inflammatory response, which results in fetal membrane rupture and cervical dilation/ripening, particularly when premature. Expression/activation is elevated during parturition, particularly when premature. While fetal membrane rupture is preceded by increases in tissue-specific MMPs, neonatal complications also ensue from an imbalance between MMPs and their tissue inhibitors. These e fects implicate environmental triggers and a genetic predisposition. MMPs are involved in the perinatal complications of prematurity and are potential targets for therapeutic intervention. Functional MMP genetic polymorphisms may assist in identifying patients at risk of complications.