Gestational diabetes and its effect on the umbilical cord

The structural changes in the umbilical cord of full term fetuses from 18 cases of gestational diabetes were studied. All these were insulin-dependent and their blood glucose levels were well controlled. Light microscopy showed rupture and erosion of the endothelial lining of umbilical arteries resulting in increased permeability and haemorrhages. The umbilical vein was unduly dilated. The smooth muscle in the walls of these vessels showed disruption and degeneration of its fibres. 'Wharton's jelly' showed alteration in the pattern of distribution of its fibres with large empty spaces amongst them. It is suggested that gestational diabetes has a deleterious effect on umbilical vessels and the connective tissue component of 'Wharton's jelly'.