BASEMENT-MEMBRANE THICKENING IN THE PLACENTAE FROM DIABETIC WOMEN

A light microscopy study was carried out on 48 placentae. Seventeen pl acentae were obtained from non-diabetic mothers while the other 31 pla centae were from both women with controlled diabetes and women who had an abnormality of the glucose tolerance test. All the women delivered at 38-40 weeks of gestation. Placentae from diabetic patients showed immaturity of the villi, hypertrophy of the capillaries and thickening of the basement membrane of the trophoblastic villi (3.2 +/- 0.35 mu m) and the amniotic membrane (1.8 +/- 0.3 mu m). Focal fibrinoid necro sis, an increase in the number of Hofbauer cells and dilatation of vil li capillaries were also commonly observed in placentae from diabetic mothers, and the normal cuboidal cells lining the amniotic membrane te nded to become tall columnar (17.6 +/- 6.3 mu m) with distally located nuclei. Similar findings were observed in patients who had a potentia lly abnormal glucose tolerance test, which suggests the possibility of primary lesion in origin. Therefore, control of hyperglycemia may onl y partially prevent the development of placental abnormalities.