The results of our study show a higher incidence of perinatal fetal morbidity (hypoglycemia, jaundice, respiratory distress syndrome) in the patients with type 1, type 2 and gestation diabetes than in the healthy controls. Also, we found a higher incidence of cesarean section in the patients with type 1 diabetes than in those with type 2, gestation diabetes and healthy controls. Although delivery in the patients with type 1, type 2 and gestational diabetes was completed approximately one to two weeks earlier compared to the healthy controls there was no statistically significant difference in the incidence of preterm delivery (≤ 36th week of gestation) between the women with diabetes and healthy controls. Preterm delivery associated with poorer glycaemic control reflected through higher values of HbA1c in third trimester. Risks from adverse pregnancy outcomes may be reduced to minimum by adequate preconception counseling of diabetic patients and early diagnosis of diabetes in pregnancy, in order to achieve glycemic control during organogenesis and within pregnancy and through the teamwork of endocrinologists, gynecologists and pediatricians.