PURPOSE: to study the histological modifications that occur in the endometrium of women before and six months after tubal ligation (TL) and to correlate these findings with progesterone (P4) levels. METHODS: the study was conducted on 16 women with normal menstrual cycles who were evaluated before and in the sixth cycle after TL. P4 levels were determined from the 8th day at 2-day intervals until ovulation and on the 8th, 10th and 12th day after ovulation or on the 24th day of the cycle. An endometrial biopsy was obtained between the 10th and 12th day after ovulation or on the 24th day of the cycle and a correlation with P4 was determined. Data were analyzed statistically by the nonparametric McNemar test for the evaluation of hormonal determination and by the exact Fisher test for the histological evaluation of the endometrium, with the level of significance set at p<0.05. RESULTS: mean age was 34.1±1.3 years. The intermenstrual interval was 27.1±2.6 days and the duration of bleeding was 3 to 5 days, with no difference between the studied periods. Before TL, 8/16 (50.0%) of the cases had a secretory endometrium according to the cycle, 3/16 (18.8%) had a secretory endometrium not according to the cycle and 3/16 (18.8%) had a dysfunctional endometrium, suggesting a defect in the luteal phase in 6/16 (37.5%). After TL, 7/16 (43.8%) had a secretory endometrium according to the cycle, 3/16 (18.8%) a secretory endometrium not according to the cycle and 4/16 (25.0%) had a dysfunctional endometrium, suggesting a defect in the luteal phase in 7/16 (43.8%). In 2/16 (12.5%) of the cases before TL and in 2/16 (12.5%) other cases after TL it was not possible to perform histological evaluation due to insufficient material or unspecfiic endometritis. In the luteal phase after TL, mean P4 levels were significantly lower on days +8, +10 and +12 than before TL, being 15.1, 18.0 and 20.7 ng/ml, respectively, before TL and 10.6, 8.0 and 5.4 ng/ml after TL (p<0.05). Before TL, 5/8 (62.5%) of the cases with a secretory endometrium according to the cycle had P4 >10 ng/ml and 3/8 (37.5%) had P4 <10 ng/ml. After TL, when the endometrium was secretory according to the cycle, P4 was >10 ng/ml in 4/7 (57.1%) and <10 ng/ml in 3/7 (42.9%). These differences were nonsignificant (p>0.05). CONCLUSION: six months after TL, the intermenstrual interval and the duration of bleeding were unchanged. P4 levels decreased during the luteal phase although this did not interfere in the endometrial response.
Endometrium; Progesterone; Sterilization, tubal
