[The course of atrial natriuretic peptide, aldosterone and antidiuretic hormone in normal pregnancy]

Atrial natriuretic peptide (ANP), consisting of 28 aminoacids, is a recently discovered cardiac hormone involved in blood-volume homeostasis. Pregnancy is associated with an increase in blood volume expansion, therefore an increase in ANP-concentration would have been expected. To test this hypothesis ANP, Aldosterone and Vasopressin, concentrations of 229 women with normal pregnancies at different gestational ages were measured and compared with values found in a non-pregnant control group of 24 women. Mean plasma ANP was increased during pregnancy, but significant differences were noted only after 36 weeks of gestation. Also plasma aldosterone increased significantly during pregnancy, whilst vasopressin levels showed no significant change compared to the non-pregnant group.