k Fifty years have elapsed since the discovery of insulin; however, pregnancy is still far from being sufficiently safe in diabetic women. The most convincing proof is given by the high perinatal mortality ranging from 10 to 15% in specialized departments [16], which would be even higher if therapeutic abortion was not performed in numerous cases of severe maternal disease [3,11,23], On the other hand, äs far äs the mother is concerned, insulin therapy has deeply changed the prognosis of pregnant diabetic patients compared with the preinsulin era. However, severe complications such äs toxemia, urinary tract infections, aggravation of vascular diseases and so forth contribute to maintain the death rate at about 1% [16, 23],
The problem of metabolic balanceIn an extensive review of the problem it has already been emphasized, many years ago [10], that unfavourable development of pregnancy and high perinatal mortality are associated specially with pregnant women lacking a good metabolic balance. These findings were subsequently confirmed [16,23] so that one may wonder whether in cases, considered to have been compensated for but still showing a high perinatal mortality rate, an actual optimal compensation had been obtained or whether its further improvement might have ameliorated fetal prognosis. As a matter of fact, the treatment of pregnant or non-pregnant diabetic patients is carried out everywhere by regulating the inCürriculum vitae GIAN sulin dosage on the basis of glycemia and glycosuria. The difficulties found in establishing the degree of metabolic compensation by means of these indices caused a considerable discrepancy of opinion äs to the optimal values for the best therapeutical approach [6,16,19,23,35,37]. On the other hand, it may be debatable whether such a criterion represents an "optimum" for the feto-placental unit in considering that the features of newborns of diabetic mothers frequently appear even in newborns of prediabetic mothers, where blood sugar levels show little or no alteration; interesting results were obtained by insulin therapy in these cases [14,22,25,41]. On the basis of the aforesaid considerations we began our investigations for a stricter control of diabetes mellitus in pregnancy in 1963. There-J. Perinat. Med. l (1973)
