In pregnancy, the most common cause of transient- diabetes insipidus is:
Severe preeclampsia
Hydramnios
Multiple pregnancy
IUGR
Diabetes insipidus can be caused by:
Deficiency of antiduretic hormone               Resistance of ADH action
                    ↓                                                                       ↓
Central diabetes insipidus                           Nephrogenic diabetes insipidus.

A transient form of DI occurs during pregnancy due to:

– Excessive placental production of vasopressinase
– Decreased hepatic clearance due to abnormal liver function there in case of:

Preeclampsia
Fatty liver
Hepatitis.


Approximately 60% of women with previously known DI worsen, 20% improve and 20% do not change during pregnancy.
Worsening is attributed to excessive placental vasopressinase production.
Some females with DI who develop placental insufficiency show DI improvement, which is attributed to decreased vasopressinase production by the damaged placenta.

Symptoms:

Polyuria (4-15 liters/day)
Intense thirst particularly for ice cold fluids.

Diagnosis: is confirmed by water deprivation test.
Treatment: of choice intranasal L-deamino 8D arginine vasopressin (DDAVP) which is a synthetic analogue of ADH and is resistant to vasopressinase.