ABSTRACT
OBJECTIVE: To investigate morphologic differences of the placenta in pregnancies complicated by gestational diabetes compared to nondiabetic pregnancies. STUDY DESIGN: This was a comparative morphological study of the placentas from 20 women with gestational diabetes and 20 healthy pregnancies at 28-35 weeks of gestation. RESULTS: The presence of lesions such as fibrinoid necrosis, villous edema, syncytial knot and vascular lesions like chorangiosis was apparent, mainly in the diabetes group. There was an apparent decrease in the intensity of the human chorionic gonadotropin (hCG) immunostaining in the syncytiotrophoblast from the 28th to 35th weeks of gestation in the placentas of the healthy control group. No hCG immunostaining was observed in the villous or intervillous areas of any of the placentas. In diabetic placentas the expression of hCG was homogeneous with a moderate to intense immunoreactivity in the syncytiotrophoblast. Several syncytiotrophoblast cells showed dilations of both rough and smooth endoplasmic reticulum and loss and alteration of microvilli, and large vacuoles were observed just below the plasma membrane, as well as irregularities in the mitochondria. CONCLUSION: Syncytial cells play an important role in the placental transition. Increased expression of beta-hCG, deterioration, degeneration of organelles and cell structure and the basal membrane disorder in chorionic vessels were seen in placentas with gestational diabetes. These changes can affect placental transfer. However, further studies are needed to clarify this issue.
