Diabetes and Pregnancy

P A R T I. GLYCOSURIA AND ACETONURIA I N PREGNANCY AND THE PUERPERIUM. * THE presence of sugar or of acetone in the urine, at one time or another, du.ring normal pregnancy and the puerpeiium is very frequently observed and, before dealing with diabetes mellitus, it is important t o study the mechanism of the benign glycosurias and acetonurias and their relation to the more serious diseases. Glycosurias of Pregnancy (1-4). These may be classified as follows :I . Early alimentary glycosuria. 2. Renal glymsuria. 3. Lactosuria. 4. Late alimentary glycosuria. (a) Hypophyseal ? (b) Carbohydrate deprivation. I . Early ulimentary glycosuria. During the first three or four months of pregnancy a lowering of the assimilation limit for carbohydrate usually occurs, so that a diet rich in carbohydrate may readily give rise to glycosuria. (510). After ingestion of 50 grammes of glucose, the curve of blood sugar may rise to about o 2 0 0 per cent. and shorn a delay in the fall (10-15). The glycosuria is due to hyperglycamia and not, as has often been supposed (16-17), simply to a lowered renal threshold for glucose. Errors of interpretation have, in the past, arisen from the blood sugar having been estimated too long after the dose of glucose, thereby missing the height of the curve, which attains its maximum in about half an hour. Once the blood sugar has exceeded the level a t which glycosuria occurs, sugar may persist in the urine for some time after the blood sugar has again fallen well below the original threshold. It is, therefore, fallacious to examine the urine