This study is aimed at assessing the effect of glycosylated hemoglobin [HbA1c) level on the pregnancy outcome in diabetic women. A follow-up study was carried out which included 169 diabetic women attending the maternity hospital and one diabetic clinic in Kuwait. An age matched control group of 80 non-diabetic pregnant women were also studied. The World Health Organization diagnostic criteria were used for ascertainment of diabetes. A standardized form was used to collect data, and all relevant investigations were carried out for diabetic and control groups. Fourteen diabetics and 4 non-diabetics were excluded due to failure to regularly attend for antenatal return visits. Eighty four [54.2%] had preconception diabetes [PCD] and 71[45.8%] had gestational diabetes [GD]. Spontaneous premature labor was recorded in 35.8% and 11.3% in PCD and GD groups respectively, compared to 10% in the control group. The rate of spontaneous abortion among PCD [9.5%] was higher than the control group [1.3%]. There was significant correlation between HbAc levels and fasting and postprandial serum blood glucose levels. Skinfold thickness of neonates were significantly higher in diabetics than controls. In conclusions HbAic levels are not particularly useful in diagnosis of diabetes, but are valuable in monitoring diabetic control and establishing the relationship of glucose control to abnormalities of diabetic status. Improvement of the perinatal outcome of diabetic patients will require a form of management that leads to reduced incidence of fetal congenital anomalies. Routine sonographic examinations of diabetic pregnancies, however, will identify a significant proportion of fetuses with major congenital anomalies, while first trimester biochemical evaluation of HbAc will identify mothers at risk of delivering anomalies infants.