Endocrine Abstracts

Introduction: Diabetes insipidus can complicate up to 1 in 30 000 pregnancies and has a variety of causes, some that predate the pregnancy and others that begin during gestation. In addition, women can experience diabetes insipidus de novo in pregnancy through the actions of placental vasopressinase, which causes accelerated degradation of vasopressin. This form of diabetes insipidus may be associated with increased complications of pregnancy, including pre-eclampsia. Management of central diabetes insipidus and transient diabetes insipidus of pregnancy can be achieved with desmopressin (DDAVP), a vasopressin analogue.

Case history: We report the management of a 36-year-old lady who was diagnosed with central Diabetes Insipidus at the age of 26. MRI Brain at the time of diagnosis showed Rathke`s cleft cyst for which she underwent transphenoidal decompression. Her Diabetes Insipidus remained well controlled on a steady dose of desmopressin (2 mcg twice a day subcutaneous injections as nasal route proved ineffective & patient did not tolerate tablets) for many years but deteriorated during her pregnancy & desmopressin dose required titrating up to 16 mcg (4 mcg four times a day) to achieve control with strict monitoring of fluid balance.

Discussion: Vasopressin requirements can increase markedly during pregnancy through placental action of vasopressinase. Patients should have pre pregnancy counselling about the potential for a deterioration in their condition and be reviewed early in the course of their pregnancy. Vasopressin and the structurally related synthetic polypeptides, desmopressin and lypressin, have been used during pregnancy to treat diabetes insipidus. No reports linking the use of vasopressin with congenital defects have been located. Oxytocic effects and increased risk of pre-eclampsia in the third trimester has been mentioned in literature with use in pregnancy.