Parturition in two pregnant women with Addison's disease: Changes of plasma corticotropin releasing factor levels

Objectives: Addison's disease is characterized by a primary adrenocortical insufficiency associated with a derangement of the hypothalamus-pituitary-adrenal axis. Before identification of cortisone supplementation therapy, only a few cases of pregnancy in Addison's patients were described. Indeed human pregnancy is characterized by a physiological state of hypercortisolemia. Corticotropin releasing factor (CRF) is a hypothalamic peptide which regulates the pituitary-adrenal cortex axis, and which is also produced during pregnancy by the human placenta, fetal membranes and decidua. In healthy women, a progressive increase of plasma CRF levels throughout gestation occurs, reaching the highest values at term and during labor, so that a placental source has been suggested. Patients and methods: The present study aimed to examine the modification of maternal CRF plasma levels at term and at parturition in two women with Addison's disease. In one patient, the disease was associated with an autoimmune hypothyroidism. Both patients had a normal pregnancy, spontaneous labor, vaginal delivery and a regular postpartum period. Plasma CRF levels were measured during the third trimester of pregnancy (at 32, 36, 40 weeks) in Case 1, while in Case 2 blood samples were drawn at the end of gestation, during labor, at delivery and from the umbilical cord. A group of normal pregnant women (n = 5) was used as a control group. Results: Plasma CRF levels during pregnancy did not differ between the Addison's patients and the healthy controls, showing a progressive increase in both groups during the last weeks of gestation. During labor and at delivery, a further significant increase of CRF plasma levels was observed in Case 2. Conclusion: These data indicate that the placental CRF pathway was not modified in these two patients with Addison's disease.