Placental immunopathology in gestational diabetes.

Gestational diabetes and insulin-dependent diabetes are characterized by distinct pathophysiological mechanisms. However, their presence in pregnancy poses similar risks to the fetus. It is possible that factors common to both diseases are responsible for the increased morbidity and mortality in offspring of such pregnancies. Recent studies of placentae from insulin-dependent diabetics revealed evidence of immunopathological change which may support the possible role of immunological factors in the complications of diabetic pregnancy. In the present study, we have similarly examined placentae derived from 30 pregnancies complicated by gestational diabetes and from 10 normal pregnancies. The most striking differences detected by immunofluorescence were increased amounts of clotting factors related to areas of fibrinoid necrosis, and large quantities of complement components C4 and C3 in the intervillous spaces and trophoblast basement membrane respectively. These results are similar to those found in placentae from insulin-dependent diabetics, suggesting that glucose intolerance in pregnancy, even of minor degree, is frequently associated with immunopathological processes that are reflected in the placenta.