OBJETIVO: estudar as modificações histológicas que ocorrem no endométrio de mulheres antes e seis meses após serem submetidas à laqueadura tubária (LT) e correlacionar esses achados com os níveis de progesterona (P4) sérica. MÉTODO: foram incluídas 16 mulheres com ciclos menstruais normais, antes e no sexto ciclo após a LT. Os níveis de P4 foram determinados a partir do 8º dia, de 2 em 2 dias até a ovulação e no 8º, 10º e 12º dia pós-ovulatório ou no 24° dia do ciclo. Realizou-se biópsia endometrial entre o 10° e 12° dia pós-ovulatório ou no 24° dia do ciclo, correlacionando com a P4. A análise estatística foi realizada com uso do teste não paramétrico de McNemar para avaliação da dosagem hormonal e o teste exato de Fisher para a avaliação histológica do endométrio, sendo considerado estatisticamente significativo p<0,05. RESULTADOS: a média de idade foi 34,1±1,3 anos. O intervalo intermenstrual foi 27,1±2,6 dias e a duração do sangramento de 3 a 5 dias, não havendo diferença entre os períodos estudados. Antes da LT, 8/16 (50,0%) dos casos tinham endométrio secretor compatível com o dia do ciclo, 3/16 (18,8%) secretor incompatível e 3/16 (18,8%) disfuncional, sugerindo defeito da fase lútea 6/16 (37,5%). Na fase pós-LT, 7/16 (43,8%) tinham endométrio secretor compatível, 3/16 (18,8%) secretor incompatível e 4/16 (25,0%) disfuncional, sugerindo defeito da fase lútea em 7/16 (43,8%). Em 2/16 (12,5%) dos casos antes da LT e outros 2/16 (12,5%) pós-LT não foi possível fazer a avaliação histológica, devido a material insuficiente ou endometrite inespecífica. Na fase lútea pós-LT, os níveis médios da P4 foram significativamente mais baixos nos dias +8, +10 e +12 do que na pré-LT, sendo na pré-LT, respectivamente, 15,1; 18,0 e 20,7 ng/ml e na pós-LT, 10,6; 8,0 e 5,4 ng/ml (p<0,05). Na pré-LT, 5/8 (62,5%) dos casos com endométrio compatível tinham P4 >10 ng/ml e 3/8 (37,5%) tinha P4 <10 ng/ml. Na pós-LT, quando o endométrio foi secretor compatível, a P4 foi >10 ng/ml em 4/7 (57,1%) e P4 <10 ng/ml em 3/7 (42,9%). Essas diferenças não foram significantes (p>0,05). CONCLUSÃO: seis meses pós-LT, não se modificaram o intervalo intermenstrual e a duração do sangramento. A P4 diminuiu durante a fase lútea, embora não tenha interferido na resposta endometrial.
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.