Effect of vitamin C on collagen structure of cardinal and uterosacral ligaments during pregnancy.

OBJECTIVE: This study aimed to investigate changes in collagen structure in the cardinal and uterosacral ligaments of rats that were administered vitamin C during pregnancy.

STUDY DESIGN: Eighteen female rats were divided into three groups: six pregnant rats administered 1.25mg/ml/day of vitamin C during pregnancy (Group A); six non-pregnant rats that were not administered vitamin C (Group B); and six pregnant rats that were not administered vitamin C during pregnancy (Group C). Fifteen days after delivery, the uteruses of all rats were removed. The intensity of staining (mild, moderate or severe) and the extent of positive staining areas (%) of type I and type III collagen H scores for types I and III collagen, and intensity of elastin fibres in the cardinal and uterosacral ligaments were investigated immunohistochemically. Differences between groups were analysed using Kruskal-Wallis and independent samples tests.

RESULTS: The intensity and extent of type I and type III collagen, the H scores for type I and type III collagen, and the ratio of type III collagen H score: type I collagen H score differed significantly between groups. Pregnant rats administered vitamin C (Group A) had significantly higher values compared with non-pregnant rats (Group B): intensity of type I collagen (p=0.001), extent of type I collagen (p≤0.001), H score for type I collagen (p≤0.001), intensity for type III collagen (p=0.002), extent of type IV collagen (p=0.007), H score for type III collagen (p=0.017), type III collagen H score: type I collagen H score (p=0.039) and intensity of elastin fibres (p=0.097). A significant difference in the ratio of type III collagen H score: type I collagen H score was found between pregnant rats administered vitamin C (Group A) and pregnant rats not administered vitamin C (Group C) (p=0.002).

CONCLUSIONS: The administration of vitamin C to rats during pregnancy had a favourable impact on collagen structure in the cardinal and uterosacral ligaments, suggesting that vitamin C supplementation during pregnancy may help to prevent pelvic organ prolapse and stress urinary incontinence.