During pregnancy, the kidneys of diabetic women undergo an elevated functional load which occurs to a greater extent if nephropathy coexists. Functional abnormalities, such as reduction of glomerular filtration rate, increase of creatinine and proteinuria, which can be observed in about 1/3 of the cases, regress or stabilize progressing only in a limited number of patients. Arterial hypertension and poor metabolic control seem to be the factors most closely correlated to the loss of renal function. Diabetic nephropathy determines an increased risk of maternal and fetal complications to be seen more frequently in women with more compromised renal function at conception, and with poor metabolic control during pregnancy. From here stems the importance of good metabolic control right from conception. Moderate physical exercise, a caloric intake of 25-35 kcal/kg/day and slight reduction of protein diet content are also advisable. Monitoring includes periodical evaluation of glycated haemoglobin, creatinine, uric acid, creatinine clearance and albuminuria not only during pregnancy but also after months or years following delivery. Arterial pressure must be monitored avoiding aggressive antihypertensive treatment. The most suitable drugs are considered alfa-methyldopa, clonidine, hydralazine and prazosine.