Collagen content and growth factor immunoexpression in uterine lower segment of type IA osteogenesis imperfecta: Relationship with recurrent uterine rupture in pregnancy

OBJECTIVE: The purpose of this study was to evaluate collagen content and platelet-derived growth factor, vascular endothelial growth factor, and connective tissue growth factor expression in the myometrium of the uterine lower segment from a patient with type A osteogenesis imperfecta with recurrent uterine rupture and to evaluate the existence of a relationship between the rare recurrent uterine rupture and the tissue disorders of type A osteogenesis imperfecta. STUDY DESIGN: Collagen content and platelet-derived growth factor, vascular endothelial growth factor, and connective tissue growth factor expression in the uterine lower segment were assessed in the patient with type A osteogenesis imperfecta and in eight otherwise healthy ("control") patients. RESULTS: Type IA osteogenesis imperfecta contained less total collagen amount, with no difference in type III collagen expression and showed increased levels of platelet-derived growth factor and vascular endothelial growth factor in myometrial smooth muscle cells. No difference was observed in connective tissue growth factor expression. CONCLUSION: These findings confirm the diminished collagen amount in myometrium from osteogenesis imperfecta and show the presence of additional pathogenetic mechanisms. A relationship is hypothesized between the underlying myometrial biochemical modifications and the recurrent uterine rupture.