It is well known that about 80% of the girls suffer from a subnormal function of the ovaries due to fibrosis which is perhaps already caused in the womb. To start puberty the brain releases follicle stimulating hormones (FSH) in order to produce estradiol (EL) in the ovaries.

Since this doesn’t happen (Hypogonadism) even more FSH is released (Hypergonadotrophy).

And if there is no oestrogen production there will be no development of the breast - only the growth of pubic hair. In addition to that the ovaries won’t develop - hence no menstruation. In subsequent years a osteopenia (reduction of bone mineralisation) is caused.

Puberty can be started if oestrogen is given orally or per transcutaneously (through the skin-patches). Sometimes an oestrogen-gestagen combination is preferred. If this hormonal substitution is stopped there will be a bleeding due to the omission.

The fact that these girls are less fertile can’t be changed by providing these hormones. The egg donation of a fertile woman - in-vitro-fertilisation with the sperm of the galactosaemic woman’s partner and the implantation of a fertilised ovum into the uterus of the GAL woman can be carried out e.g. in the USA.

It is very important that the children - and adult endocrinologist and the gynaecologist work in collaboration.