With the use of two central health registries in Sweden, the Hospital Discharge Registry and the Medical Birth Registry, we identified 100 infants born of women who had been hospitalized for diabetes insipidus. By checking the medical records of these women, 29 infants were identified whose mothers had diabetes insipidus prior to the pregnancy and had been treated through the pregnancy with desmopressin. These infants had a normal birth weight and gestational length; there was only one congenital malformation identified (a ventricular septum defect with a patent ductus arteriosus and simian lines). This child died at the age of 14 years in a hypophyseal disease. This is the largest material published on desmopressin during pregnancy. The results suggest that maternal diabetes insipidus and treatment with desmopressin during the whole pregnancy does not constitute a major risk for the infant.