Ultrasonographic endometrial monitoring during continuous-sequential hormonal replacement therapy regimen in...

To evaluate the endometrial thickness in different periods of a continuous-sequential HRT regimen and to correlate the ultrasonographic findings with the histological patterns.

The study was structured in two phases. In the 1st phase, 37 postmenopausal women (group A) treated by at least 6 months with a conventional continuous-sequential hormonal replacement therapy (cs-HRT) regimen were enrolled. In all patients, the endometrial thickness was measured at the 7th, 14th, 21st and 25th day of the cycle using transvaginal ultrasonography (TV-USG). In the 2nd phase of the study, other 41 postmenopausal women (group B) were enrolled and treated with the same sc-HRT regimen. At entry and after six cycles of cs-HRT, an endometrial biopsy was performed. The endometrial pattern was related with endometrial thickness. Either the evaluations were performed immediately after progestogen withdrawal bleeding, as showed by 1st phase results.

The results of the 1st phase of the study showed a mean endometrial thickness significantly lower at 7th day of the cycle compared to 14th, 21st and 25th day (4.3+/-1.2 versus 6.6+/-2.9, 7.8+/-4.2 and 7.4+/-4.6 mm+/-SD, respectively). After six cycles of cs-HRT (2nd phase of the study), the mean endometrial thickness was significantly increased in comparison with basal values (4.2+/-1.5 versus 2.8+/-1.2 mm+/-SD; P<0.05). Endometrial biopsies showed 13 cases (39.4%) of atrophy and 20 cases (60.6%) of proliferative endometrium. Mean endometrial thickness in case of atrophy was lower than in presence of a proliferative endometrium (3.7+/-1.2 versus 4.4+/-1.4 mm+/-SD; not significant). Endometrial thickness was <4 mm in 16 cases (11 of atrophic and five of proliferative endometrium), between 4 and 5 mm in 15 cases (13 of proliferative and two of atrophic endometrium) and between 5 and 6 mm in two cases (either case of proliferative endometrium).

The best timing for monitoring endometrial thickness during cs-HRT regimens is the period immediately after withdrawal bleeding improving the reliability of the ultrasonographic exam to identify endometrial pathologies.