In the absence of many formal studies of oestrogen replacement in young women, most of the protocols in use for induction of puberty are empirical and vary from country to country depending on which products are readily available. There is growing evidence that transdermal oestrogen is the favoured option for the induction of puberty allowing an early start to treatment and a closer mimic to normal puberty. This is achieved using fractions of matrix patches containing oestradiol.
Oestradiol has become the mainstay of all forms of oestrogen replacement as opposed to conjugated equine oestrogen or ethinylestradiol. Ethinylestradiol still has a place however, only in those conditions where spontaneous resolution is possible and contraceptive cover is required such as idiopathic POI and hypogonadotrophic hypogonadism.
The dose of oestradiol is adjusted mainly based on symptoms with little need for measurement of LH, FSH or oestradiol. The pace of dose increments in the induction of puberty can be adjusted according to uterine measurements based on transabdominal ultrasound if available. This form of bioassay is useful in order to quickly identify those that require unusually high doses. The timing of first exposure to oestrogen in girls has been gradually brought forward with growing confidence that normalisation of puberty takes priority over a possible adverse effect on final height particularly in girls with Turner syndrome.