Aim of the study.
Special interest has been given to changes in the quantity and quality of the periurethral collagen (1,2) in relation to the development of genuine stress incontinence(GSI) in women. It has been reported that total collagen reduction of the pubocervical fascia is associated with the development of G.S.I(1) and collagen production from the fibroblasts is reduced by 30% in women with GSI (3), but there is very limited information about changes in specific types of collagen in relation to the development of G.S.I. Objective of this study was to determine possible changes in the quantity of type III collagen and changes in the distribution and structure of collagen fibers for the formation of fascial network in women with G.S.I and with pelvic relaxation or not.

Methods.
Eighty-six women participated in the study and they were divided in to three groups as follow : 34 patients with G.S.I and pelvic relaxation (group 1), 32 patients with pelvic relaxation but without G.S.I (group 2) and 20 patients with neither pelvic relaxation nor G.S.I (group 3). All the women underwent a complete preoperative urodynamic evaluation. Biopsies were obtained during surgery from the pubocervical fascia. The presence of collagen type III was determined by immunohistochemical technique and the structure and organization of collagen fibers was examined under the microscope using a magnification of 20X. The specimens were examined by two independent histopathologists. Specimens with disagreement between the examiners about the findings were excluded from the study.The Student's test was used for statistical analysis. A p<0.05 was considered statistically significant.

Results.
All groups of patients were comparable in respect to age, parity and body mass index. Groups 1 and 2 were also comparable in respect to the degree of pelvic relaxation. Urodynamic studies confirmed the diagnosis of G.S.I. Collagen type III was significantly reduced (p<0.05) in patients with G.S.I and pelvic relaxation (group 1), compared to patients in groups 2 and 3. Specimens from women without G.S.I ( group 2 and group 3) had a similar density of collagen type III(Table I). Also, was noted a breaking of collagen fiber's bundles in association with a more abnormal distribution of collagen fiber's bundles, leaving gaps in the continuity of fascial network of the pubocervical fascia in women with significant prolapse.

Conclusion.
In this study, we found that women with G.S.I had less collagen type III around the urethra regardless of the degree of pelvic relaxation. It appears that collagen content of the pubocervical fascia has a significant role in the maintenance of urinary continence but the mechanism by which collagen metabolism is altered remains unknown. Also, it appears that the development of genital prolapse is probably associated with breaking of collagen fibers bundles, but further studies are needed for safe conclusions to be made.

References.
1. Am J Obstet Gynecol 1998; 179: 1511-1514.
2. Acta Obstet Gynecol Scand 1987; 66: 455-457.
3. Obstet Gynecol 1994; 84: 583- 586.

Table I. Findings of collagen type III in the pubocervical fascia of the three groups.

SUI: Stress urinary incontinence .