Uterine dehiscence in term pregnant patients with one previous cesarean delivery: growth factor immunoexpression and collagen content in the scarred lower uterine segment.

OBJECTIVE: This study aimed at investigating the relationship between the occurrence of uterine dehiscence in term pregnant scarred uteri and the presence of altered biochemical behavior of the scarring process.

STUDY DESIGN: Collagen content and the expression of transforming growth factor-beta and its isoforms transforming growth factor-beta1 and transforming growth factor-beta3, connective tissue growth factor, basic fibroblast growth factor, vascular endothelial growth factor, platelet-derived growth factor, and tumor necrosis factor-alpha in myometrium of lower uterine segment were assessed in 19 otherwise healthy term patients with one previous cesarean delivery who were not in labor. We were searching for differences between patients who showed uterine dehiscence (9 cases) and patients who showed a normal-appearing scarred lower uterine segment (10 cases). We also evaluated all these features in lower uterine segment from unscarred uteri of 10 otherwise healthy patients who were not in labor.

RESULTS: In the case of uterine dehiscence, the scarred lower uterine segment showed a higher collagen content, a reduction of pan transforming growth factor-beta expression because of a marked decrease or absence of transforming growth factor-beta3, a reduction of connective tissue growth factor, an increase in basic fibroblast growth factor and a slight enhancement in vascular endothelial growth factor, platelet-derived growth factor, and tumor necrosis factor-alpha expression.

CONCLUSION: These findings contribute to meliorate our knowledge about uterine scar healing and allow us to hypothesize that uterine dehiscence of a scarred uterus may be related to altered biochemical behavior of the scarring process.