A critical appraisal of the evidence for improved fertility indices in undescended testes after gonadotrophin-releasing hormone therapy and orchidopexy.

Male fertility depends on the transformation of gonocytes into dark adult spermatogonia, during the first 3 months of postnatal life, and this is an androgen-dependent process. This essential developmental step appears to be defective in undescended testes, and in many patients orchidopexy alone (at the age it is currently performed) does not improve fertility indices, either because it does not address the underlying pathophysiology or the surgery is performed too late. Hormone therapy with gonadotrophin-releasing hormone creates a rise in testosterone levels, copying the postnatal gonadotrophin surge. This can improve germ cell numbers, with the implication of enhanced longer-term fertility. The role of hormone therapy has been controversial, and although favoured at the European Society of Paediatric Urologists' workshops in 2008 and 2009, it is not routine clinical practice in the UK or other countries. We performed a critical appraisal of the key papers in the world literature to evaluate the level of evidence for improved fertility indices, semen analysis and paternity rates following hormone therapy in undescended testes. We suggest that the evidence is sufficiently strong to recommend a change in clinical practice.