Severe hydramnios and preterm delivery in association with transient maternal diabetes insipidus.
BACKGROUND
Diabetes insipidus is rare in pregnancy. It is characterized by hypoosmolar polyuria and may be central, nephrogenic, or transient in etiology; the latter is presumably related to excess placental vasopresinase production. In theory, fetal effects of this endocrine condition may include hydramnios secondary to fetal polyuria.


METHODS
A pregnant patient developed rapid-onset second-trimester hydramnios that prompted a thorough fetal and maternal evaluation. She ultimately was diagnosed with transient diabetes insipidus of pregnancy because of an abrupt change in her voiding pattern at 20 weeks of gestation, significant polydipsia, and laboratory studies that revealed a hypoosmolar polyuria with normal serum and urine electrolytes. Transient neonatal polyuria also was confirmed in association with this unique maternal endocrine syndrome.


CONCLUSIONS
The most likely cause of hydramnios in this case is transient maternal diabetes insipidus of pregnancy from excessive secretion of placental vasopressinase resulting in fetal polyuria. In cases of hydramnios of unknown etiology, if a history of maternal polyuria is elicited and confirmed, diabetes insipidus of pregnancy may play a role in some cases.
Weinberg
Lori E
LE
From the Northwestern University Feinberg School of Medicine Department of Obstetrics and Gynecology, Chicago, Illinois; and the NorthShore University HealthSystem Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Evanston, Illinois.
Dinsmoor
Mara J
MJ
Silver
Richard K
RK
D000328:Adult; D003919:Diabetes Insipidus / Q000150:complications*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D006831:Polyhydramnios / Q000209:etiology*; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000209:etiology*