Inhibins and activins in human ovulation, conception and pregnancy

The activins and inhibins are glycoproteins that belong to the transforming growth factor-beta superfamily and, as such, have diverse effects at many stages during growth and development. Originally identified by their effects on follicle stimulating hormone in males and females, the recent development of specific and sensitive assays for this group of polypeptides has permitted the elucidation of their role in 'fine-tuning' the hypothalamic-pituitary-gonadal axis. This review article focuses on the roles of inhibin and activin in female reproductive physiology with reference to possible future clinical applications in the investigation of infertility and abnormal pregnancy.