Demonstration of reserved anterior pituitary function among patients with amenorrhea after postpartum hemorrhage.

To demonstrate the residual pituitary function of patients with Sheehan's syndrome years after the obstetric complication, 14 patients with postpartum hemorrhage followed by secondary amenorrhea and agalactia were included in this review. Due to their unfamiliarity with the clinical symptoms, these patients did not receive pretreatment hormonal therapy. The mean age at their last delivery was 29 years (range 21-38 years). The mean duration between postpartum hemorrhage and the subsequent clinical manifestations leading to the endocrine investigation was 18 years (range 1-33 years). Eight patients presented with symptoms of severe hyponatremia (serum sodium less than 125 mmol/l) more than 16 years (mean 23 +/- 10) after the occurrence of postpartum hemorrhage. The electrolyte abnormality was primarily due to adrenal dysfunction. Seven out of 14 patients had normal basal luteinizing hormone (LH) levels and adequate LH responses to gonadotropin releasing hormone stimulation. Administration of thyrotropin releasing hormone provoked thyrotropin release and/or prolactin secretion in four cases. The manifestation of clinical hypopituitarism and the degree of empty sella on computed tomography scanning did not accurately indicate the secreting ability of the pituitary in patients with Sheehan's syndrome. Although all the patients had amenorrhea, the gonadotropic functions of the pituitary still remain in some patients. Various degrees of other pituitary functions can also been demonstrated even several decades after the occurrence of obstetric complications. Our data suggest that the amenorrhea of Sheehan's patients is not simply due to a dysfunction of the pituitary gonadotrophs.