To investigate the influence of obstetric factors and indices of maternal metabolic control on perinatal morbidity and mortality, 88 diabetic pregnant Sudanese women (type 1, n=38; type 2, n=31; gestational diabetes, n=19) and 50 non-diabetic pregnant control women were studied. The mean fasting blood glucose was 11.1+/-2.8 mmol/l and the mean HbA(1c) at booking interview was 8.8+/-2.1% in the diabetic women. Pregnancy complications such as Caesarean sections, urinary tract infections, pregnancy-induced hypertension and intrauterine foetal death were higher among diabetic compared with control women (P<0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (54.4% vs. 20.0%; P<0.0001). Infants without complications and who were born to diabetic mothers had better Apgar scores at 5 min (9.8+/-0.5 vs. 8.9+/-1.6; P<0.01) and lower cord C-peptide when compared to infants with complications (P<0.05). In conclusion, the prevalence of maternal and neonatal complications among Sudanese diabetic women and their infants is high. Maternal hyperglycaemia is an important factor affecting maternal wellbeing and neonatal morbidity and mortality.