Uterine Development After Estrogen Replacement Therapy in Women with Different Etiologies of Primary Hypogonadism

Study Objective: To evaluate uterine development with estrogen replacement therapy in patients with primary amenorrhea due to hypogonadism. Design and Setting: Retrospective study. Participants: Thirty-five women. Interventions and Main Outcome Measures: Women who were younger than 20 years of age and who had primary amenorrhea and an immaturely shaped uterus were included. Changes in uterine cross-sectional area (UXA) and uterine maturity in pelvic ultrasound after 2 year of estrogen replacement therapy were assessed on the basis of the etiology of primary hypogonadism. Results: Patients were classified into three groups according to the etiology of primary hypogonadism: Turner syndrome (n = 19), hypogonadotropic hypogonadism after brain surgery (n = 10), and premature ovarian insufficiency after cancer treatment (n = 6). Overall, the mean UXA significantly increased (from 3.1 ± 1.8 to 11.6 ± 4.9 cm²) after estrogen replacement therapy (P < .001), but the final UXA was significantly smaller in patients with premature ovarian insufficiency compared with other etiologies. In logistic regression analysis, etiology and the cumulative dose of estrogen were associated with uterine maturation (P = .011 and .004, respectively). Conclusion: Estrogen replacement therapy induced growth of the uterus in patients with primary hypogonadism. However, the response to estrogen replacement therapy varied on the basis of the total cumulative dose of estrogen and etiology of primary hypogonadism.