It has become apparent that the reproductive and somatotrophic axes may often be interlinked, and that the ovary may be a target for growth hormone action. Within the ovary, there exists a complex regulating system involving growth factors, which promote gonadotrophin action, and their binding proteins, which modulate these actions. The realization of the existence of this fine-tuning system has prompted clinical trials of cotreatment with growth hormone and gonadotrophins, mainly directed at the poor responder to gonadotrophin stimulation. The effect of this treatment is dependent on the hormonal status and 'ovarian age' of the patient. Studies have delineated a possible role for additional growth hormone in those with a lack of growth hormone but it has little place in a normal system. Although an improvement in pregnancy rate has not yet emerged, more research should be forthcoming on the effect of growth hormone and growth factors on the follicle, oocyte and endometrium and their possible role in polycystic ovary syndrome.