Ultrastructure of the villi and fetal capillaries of the placentas delivered by non-smoking diabetic women (White group D).

The ultrastructure of the placentas from nine non-smoking. White group D diabetic women were studied. The terminal villi showed changes in maturation, increased vascularization mainly due to very small vessels located at the periphery of the villus, and glycogen accumulation within the stroma cells and pericytes, corresponding to the known higher glycogen content of diabetic placentas. Multilaminal basement membrane surrounded the capillaries, but great variation appeared possibly due to variation in capillary age. It is suggested that diabetic metabolism induces a proliferative small vessel disease in combination with accelerated aging.