During recent years, we have accumulated considerable data on the general question of nitrogen retention in the blood during the late toxemias of pregnancy; and, in view of the divergent opinions that prevail concerning the value of such determinations in the differential diagnosis and prognosis of these conditions, it seems that they should be recorded. Our investigations have led us to believe that blood chemical studies are at present of little or no practical assistance in the
clinical management of these cases, and that the older methods of examination—urinalysis, blood pressure readings and ophthalmoscopy—yield the most valuable information concerning the patient's condition.
Previous workers (Folin,1 Caldwell and Lyle,2 Killian and Sherwin,3 de Wesselow 4 and others) have demonstrated that the substances studied (total non
protein nitrogen, urea and uric acid) occur in normal concentrations in the blood during normal gestation. They have, moreover, pointed out that there
PLASS ED. NONPROTEIN NITROGENOUS CONSTITUENTS OF BLOOD IN ECLAMPSIA AND ALLIED CONDITIONS. JAMA. 1924;82(4):266–269. doi:10.1001/jama.1924.02650300012004