Efficacy of estrogen replacement therapy (ERT) on uterine growth and acquisition of bone mass in patients with Turner syndrome.

Estrogen replacement therapy (ERT) is necessary for uterine development and bone mass acquisition in women with Turner syndrome (TS) suffering from ovarian insufficiency. However, adequate ERT regimens have not yet been established. The aim of this study was to evaluate the efficacy of ERT for both uterine development and bone mass acquisition. One hundred TS patients from Yokohama City University Hospital (88 with primary amenorrhea (PA) and 12 patients with spontaneous menstrual cycles (MC)) were enrolled after obtaining consent. Clinical profiles, uterine length (UL) measured by ultrasonic examination, and bone mineral density (BMD) of the lumbar vertebrae (L2-4) assessed by DEXA were evaluated. At the time of the first visit, the ULs of patients in the PA group were significantly shorter than those in the MC group. After receiving ERT, there were no significant differences in UL between patients with PA and MC. Forty-seven patients for whom the ERT initiation age was known were investigated to clarify the influence on BMD. The results showed that the BMD in the late initiation (18 years or older) group at the latest visit (0.770 ± 0.107 g/cm2: n = 16) was significantly lower than that in the early initiation (under 18 years) group (0.858 ± 0.119 g/cm2: n = 21) or the MC group (0.941 ± 0.118 g/cm2: n = 10). No significant differences were seen between the early initiation and MC group. ERT was effective in increasing UL and BMD. However, early initiation of ERT is necessary to increase BMD.