Impact of menopause on collagen subtypes in the arcus tendineous fasciae pelvis.

OBJECTIVE

The arcus tendineous fasciae pelvis (ATFP) provides support to the anterior vagina. The objective of this study was to determine the impact of menopause on the structural components of the ATFP.

STUDY DESIGN

Biopsy specimens of the ATFP were obtained from 10 premenopausal, 5 postmenopausal, and 12 postmenopausal women on hormone therapy. Scanning confocal microscopy of fluorescent micrographs was used to define the amount of collagen subtypes, smooth muscle, and elastin. Collagen fiber orientation was determined by scanning electron microscopy.

RESULTS

The ATFP is comprised primarily of parallel bundles of type III collagen fibers (84%), an intermediate amount of elastin (13%), and very little smooth muscle. The ratio of collagen I/(III+V) was decreased in postmenopausal not on hormones relative to premenopausal women (P=.04) due to a 75% decrease in collagen I (P=.046). The decrease in collagen I and change in collagen ratios was not present in women on hormone therapy. Comparison of the amounts of elastin and smooth muscle showed no difference in the ATFP of premenopausal and postmenopausal women.

CONCLUSION

Menopause in the absence of hormone therapy is associated with a decrease in quantity of collagen I in the ATFP resulting in a decrease in the ratio of collagen I/(III+V). This may compromise the tensile strength and an increase susceptibility to anterior vaginal wall prolapse.