Azar Danesh Shahraki - Department of Obstetrics and Gynecology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Azam Zafarbakhsh, - Department of Obstetrics and Gynecology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
Amirreza Farhadian Dehkordi - Department of Obstetrics and Gynecology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Introduction: Polyuria is a common complication in pregnancy, but it should be distinguished from polyuria due to diabetes insipidus with low urinary osmolality. Diabetes insipidus (DI) can occur as primary, central and nephrogenic. Transient DI contributed to changes in pregnancy, especially in twin pregnancy or subsequent to preeclampsia, HELLP syndrome, fatty liver, hepatitis or cirrhosis. Sometimes the disease is sub-acute and it is less symptomized during pregnancy. Recognition and treatment of DI cause in pregnancy is important because the fluid restriction can lead to hypernatremia with major manifestations such as neurological symptoms including restlessness, weakness, decreased consciousness, delirium, seizures or coma.The first case:A pregnant woman that was 37 years old with two alive and healthy children with positive family history of nephrogenic diabetes insipidus in her brother. During the second pregnancy, the pregnant woman developed severe polyuria and polydipsia. Gestational Diabetes Mellitus (GDM) was diagnosed, according to an impairment oral glucose tolerance test (OGTT) and underwent the treatment. The laboratory tests were normal, except urine specific gravity=1004.The second case:The patient was a 28-year-old woman with central DI that suffered from the disease following the inner ear surgery and pituitary gland injury at age two.Conclusion:If the causes of diabetes insipidus in pregnancy are well recognized and treated, it can prevent maternal and fetal complications.