Changes in Collagen Content of the First Trimester Cervix Uteri after Treatment with Prostaglandin F2α Gel

Abstract

A reduction of the total collagen content of the cervix in advanced pregnancy has been observed by previous investigators. The present authors report the effect of prostaglandins on the hydroxyproline content of the pregnant cervix. Tissue samples were taken from the posterior lip of the cervix in 27 patients who had had abortions between the 7th and 1 2th weeks of pregnancy and subsequent laparoscopic sterilization. Eight hours before the samples were taken, 17 patients had intracervical applications of prostaglandin F2α. The other 10 patients received no prostaglandin treatment. The age of the patients ranged from 28 to 42 years. Quantitative amino acid analyses from different tissue depths of the cervix uteri between 5 and 10 mm showed no significant differences in the amount of hydroxyproline. The distribution of individual hydroxyproline values showed a large variation in both groups, but there was a definite tendency toward lower values, indicative of collagen loss, in the prostaglandin-treated group. In the untreated group, hydroxyproline values tended to be lower as gestation advanced. There was a reduction in the mean hydroxyproline value from 80 to 68.6 per cent 8 hours after prostaglandin treatment. The significance of this difference is made clear by the hydroxyproline distribution function (Fig. 1). This reflects the cumulated frequencies in the individual collectives, i.e., for each value on the abscissa, the function of tissue samples with hydroxyproline content equal to or less than this value is given. Lower hydroxyproline values were generally found in the prostaglandin-treated tissue samples, 50 per cent of them having a hydroxyproline content below 70 per cent. Only 20 per cent in the untreated group had such a low content. The significance of this difference was confirmed by a Wilcoxon test (P = 0.016).