This study was designed to test the feasibility of a patient-monitored glucose determination program to establish and maintain normal blood glucose levels. Ten pregnant women, who were insulin-dependent diabetics prior to becoming pregnant and who were in their eighth week or less of pregnancy, were offered the program. All 10 accepted and continued the program for the duration of their pregnancy. Normal plasma glucose (60 to 140; mean = 80 mg/dl) levels were achieved after one week of the program and were maintained throughout the pregnancy as documented by 5 to 8 blood glucose determinations a day. The hemoglobin A1c level, which was elevated in all 10 patients at the start (9.4 +/- 1.6 per cent) of the program, fell into the normal range (2 to 5.0 per cent) five weeks after glucose values became normal. Serum estradiol (0.8 +/- 0.6 ng/ml), serum prolactin (10 +/- 9 ng/ml) and serum human chorionic gonadotropin (5,500 +/- 1,700 ng/ml), although all abnormal at the start of the program, became normal after glucose control was achieved (program weeks 4, 5 and 6, respectively). The infants showed no signs of macrosomnia (2,988 +/- 959 g), hypoglycemia, hyperbilirubinemia, hypocalcemia, erythremia or respiratory distress. Therefore, a program to maintain normal blood glucose levels during a diabetic patient's pregnancy is not only possible but may also improve the pregnancy and the outcome.