TRANSIENT DIABETES-INSIPIDUS IN PREGNANCY - A CONSEQUENCE OF ENHANCEDPLACENTAL CLEARANCE OF ARGININE-VASOPRESSIN

We report a patient who presented with transient diabetes insipidus in pregnancy on a background of previous postoperative diabetes insipidu s following surgical excision of a prolactinoma, The patient illustrat es how the complex changes in water homeostasis occurring during norma l pregnancy may unmask latent diabetes insipidus, The major factors op erating appear to be a physiological reduction in the thresholds for t hirst and arginine vasopressin secretion coupled with a substantial in crease in placental clearance of arginine vasopressin. Reversal of the se changes after delivery results in normalization of the disordered w ater homeostasis, with consequent resolution of the diabetes insipidus .