Oestrogen treatment of tall girls: effect decreases with age

Fifty-nine tall girls were treated with oestrogen to reduce final height, starting at the ages of 9.1 to 16.2 years. We assessed the result of this treatment by comparison with matched controls. The epiphyseal bone age at the start of therapy, the final height, the Bayley-Pinneau (BP) and Roche-Wainer-Thissen (RWT) predictions of final height, and the errors in both predictions were evaluated. The matched pairs were divided into three groups according to bone age at the start of treatment; I less than 10.5 (n = 16), II 10.5-12.0 (n = 22) and III greater than 12.0 years (n = 21). The mean (SD) intrapair reduction of height for these groups was 9.7 (4.0) cm, 4.3 (4.3) cm and 3.5 (3.2) cm, respectively, according to BP predictions and 6.3 (4.3) cm, 3.4 (3.0) cm and 1.2 (3.3) cm according to RWT predictions. No method of predicting height is accurate for tall girls and simultaneous predictions may differ greatly. Close agreement between the BP and RWT predictions does not indicate greater accuracy. The earlier therapy is started, the greater is the effect. Young girls need psychosocial support with therapy.