Endocrine Abstracts

Fertility preservation is a rapidly advancing area of medicine. Its clinical potential in adult women was demonstrated by ovarian function and successful pregnancy following ovarian cortical tissue cyropreservation and replacement in the sheep in the 1990s with the first successful human pregnancy reported in 2004. Since then some 25 babies have been born to women who have had ovarian tissue cryopreserved and subsequently replaced, with most of these women having been treated for haematological malignancies. Much larger numbers of women have had embryo cryopreservation, which has long been a routine in IVF practice, and recent developments in oocyte vitrification have made that approach a much more viable option than was the case just a few years ago. For children however gonadal tissue storage remains the only option. Several case studies have been published showing its application to girls, and there are two reports of replacement of ovarian tissue to induce puberty in adolescent girls, although this indication is debatable. Options for boys remain experimental at present. Ovarian tissue harvesting requires a surgical intervention and therefore patient selection is of paramount importance. This is to ensure that only children at high risk of losing their fertility undergo such an additional procedure, and to minimise the risk of complications. Additional issues include the loss of a large proportion of the cryopreserved ovarian follicles following re-implantation, and the risk of re-implanting the original malignancies. Despite these significant issues it appears that this is a reasonable option at present for a small proportion of girls with newly diagnosed cancer.