This study reviewed the histopathology of endometrial curettings following spontaneous abortion in diabetics and controls. The two groups did not differ significantly for an array of histologic features. The relationships between histopathology and diabetic White class, diabetic nephropathy or retinopathy, first trimester hemoglobin A1 percentage, and first trimester serum magnesium level were studied. The only significant correlation found was between diabetic retinopathy and decidual congestion with the presence of venous fibrin.