Maternal Diabetes as a Risk Factor for Congenital Heart Defects in Infants of Diabetic Mothers.

Congenital heart disease is defined as a gross structural abnormality of the heart or intra-thoracic great vessels that is actually or potentially of functional significance .The prevalence of CHD at birth has been relatively variable at 4.05 to 10.4 cases per 1000 live births in different surveys however,it is 5.0% in infants of diabetic mothers (IDMs).CHD is the most common congenital problem in children accounting for nearly 25% of all congenital malformations .CHDs are one of the significant causes of infant morbidity and mortality. Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy. It is associated with maternal and neonatal adverse outcomes. Maintaining adequate blood glucose levels in GDM reduces morbidity for both mother and baby. Pregnancy is associated with insulin resistance (IR) and hyperinsulinemia that may predispose some women to develop diabetes. Gestational diabetes has been defined as any degree of glucose intolerance with an onset, or first recognition during pregnancy. Diabetes during pregnancy could be a de novo that arises during pregnancy for the first time and could disappear or persist after delivery (gestational DM) or could start as pre-gestational, before the onset of pregnancy. The incidence of impaired glucose tolerance in pregnancy ranges between 3-10% and varies according to the average incidence of diabetes in the general Population. Specific CHDs that are more commonly seen in IDMs include ventricular septal defect (VSD), transposition of the great arteries (TGAs), and aortic stenosis (AS).Approximately one third of neonates with CHD require intervention in the first month of life . Clinical manifestation of CHD varies according to the type of lesion. Neonates with respiratory distress , cyanosis, feeding difficulties, and low cardiac output are common presentations of CHD . So diagnosis of CHD at the earliest possible time is very important as early referral and appropriate intervention in some of these cases are lifesaving.