A stereologic study of postmature placentas fixed by dual perfusion

OBJECTIVE: Placental insufficiency has been considered the cause of increased morbidity in infants delivered postmaturely. Former quantitative studies have indicated a decrease in some placental structures just before term. In this study we describe a method of dual perfusion fixation to provide tissue for stereologic examination. Postmature placentas were examined with this method. STUDY DESIGN: Eleven postmature placentas and 14 placentas deliverred at term were fixed by dual perfusion. The volume and the surface area of villi, the trophoblast volume, and the volume, surface area, and length of villous capillaries were estimated by stereologic examination. The Mann-Whitney test (p ≤ 0.05) was used for statistical analysis. RESULTS: Morphologic features were normal in all placentas. No significant differences were disclosed in the stereologic estimates of placentas delivered at term and postmature placentas. CONCLUSION: No morphologic or significant quantiative changes were found in postmature placentas.