In this study we concluded that usefulness of sonographic umbilical cord thickness, interventricular septum thickness and HbA1c in prediction of fetal macrosomia in Patients with gestational diabetes mellitus. Umbilical cord area measurement may be combined with the standard fetal biometric parameters to improve the accuracy of identification of fetal macrosomia, allowing it to be better managed without unnecessary intervention, while possibly avoiding permanent injury. Fetal hyperinsulinism in combination with the normally increased expression and affinity of fetal insulin receptors can lead to proliferation and hypertrophy of cardiac myocytes. Hypertrophic cardiomyopathy is characterized by thickening of the interventricular septum, and to a lesser degree, the ventricular free walls. It is usually asymptomatic and resolves within the first year of life,. The rate of meconium aspiration and the need for mechanical ventilatory support are increased in this group of neonates. Maternal complications such as postpartum hemorrhage, infections, aswell as third- or fourth-degree vaginal lacerations may occur as a result of operative delivery