Laminin and Collagen IV: Two Polypeptides as Marker of Dystocic Labor

Abstract

Collagen IV and Laminin are localized in cells and tissue of numerous human organs including the uterus, where these polypeptides control either age changes, or uterus growth in pregnancy, or ripening and dilatation in labor. Authors examined the polypeptides distribution of collagen IV and Laminin in the human pregnant uterus, in normal and dystocic labor, to clarify their physiologic role, by distribution and/or their changes in prolonged dystocic labor. We collected lower uterine segment (LUS) fragments during cesarean section (CS); these biopsies were treated with basic morphological staining for the observation of microscopic- anatomic details. Other samples were processed with immunohistochemical staining for collagen IV and for membrane bound Laminin. All morphological and immunochemical results were analyzed with quantitative analysis of images and statistical analysis of data. Both Collagen IV and Laminin show changes in the pregnant uterus before 4 hours of full cervical dilatation in patients after 4 hours. All the three types of the human uterine cells, mucosal, submucosal and smooth muscular cells, are more reduced in LUS after 4 hours of cervical dilatation in dystocic labor. The connective tissues (including fibroblast) show the most evident changes in the dystocic LUS, collagen IV and laminin changes during cervical dilatation in prolonged dystocic labor, with a decreased elasticity with increased roughness and dryness. The LUS anatomical modifications during labor can be the cause of pathological changes in protracted dystocic labor. In the dystocic labor that lasts more than 4 hours from the complete cervical ripening and dilatation, the laminin and collagen IV concentration reduces in the LUS tissue. In dystocic labor, delivery should be completed before the 3 hours of full dilation, to avoid a reduction of laminin and collagen IV and a worsening of LUS healing for the next pregnancy.

Keywords: Collagen IV; Dystocia; Laminin; cesarean section; lower uterine segment; obstructed labor; uterine cervix.