Effect of enhanced vaginal acidity on structure and softness of the uterine cervix prior to dilatation in gynaecologic operations: a clinical and histological study

Cervical dilatation along with hysteroscopy or endometrial curettage, is one of the most common procedures in gynaecological practice. Traumatic complications, such as uterine perforation and cervical laceration, which may occur during dilatation of cervix are related to the degree of difficulty of cervical dilatation. The incidence of these complications may be reduced if the cervix is softened [primed] beforehand. This study aimed to evaluate the efficacy of increasing vaginal acidity by 2% acetic acid tablets in cervical softening [priming] in women undergoing cervical dilatation operation along with assessment of the structural changes in cervical tissue. The study included 30 nulligravidae which were divided equally to receive either neutral vaginal tablets [control placebo group] or acetic acid 2% vaginal tablets [acid treated group]. For the two groups tablets were taken once /12 hours for 5 days. After routine preparation of the operation, the base line cervical dilatation was assessed by Hegar's dilator application. If the cervix was less than 8 mm, it was dilated and easiness of dilation was assessed by Likert's scale. For the histological study cervical biopsies were taken from subjects of both groups and were fixed in 10% formalin. Paraffin sections were prepared for light microscopy examination. A morphometric and statistical study was also done for the mean area percent of collagen. Clinically, the overall cervical priming effect was significantly higher in the acid treated group when compared with the placebo control group. Histological study revealed that in acid treated group, the collagen fibers underneath the epithelial lining and in-between the cervical glands appeared separated and dissociated. Marked infiltration with neutrophils was also observed. There was a significant decrease in the mean area percentage of collagen content when compared with the control placebo group. The epithelial lining and the cervical glands showed no structural changes and appeared nearly similar to the control group. It was concluded that increased vaginal acidification with 2% acetic acid could be effective as a cervical priming agent which might be useful in many gynaecologic manipulations