Variability of response to early puberty induction demonstrated by transverse uterine diameter measurement and a novel method of 3D breast imaging.

We demonstrate variation in response to exogenous oestrogen, emphasising the necessity for individualised dose titration. In the absence of sensitive oestradiol assays, uterine transverse measurements may be used as a surrogate marker of oestrogen sensitivity to guide early dose adjustment. 3D breast imaging may provide a quantitative assessment of breast development to complement Tanner breast staging.