Study On The Correlation Between Fetal Nucleated Red Blood Cells In Maternal Blood And Placental Injuries

Placental injuries can affect material exchange between pregnant women and fetus, causing fetal hypoxia, fetal distress, fetal growth restriction, hypertension disorder com- plicating pregnancy, and other diseases. These diseases would also cause or aggravate the placental injury, which forms vicious cycle and harms pregnant women as well as fetus. Therefore, it is of important clinical significance to find out pregnancy status and fetal development based on the knowledge of the extent of placental injuries. This thesis is designed to reflect the severity of placental injury by analyzing the number of FNRBC (fetal nucleated red blood cells, FNRBC) in maternal blood, and to study the relationship between FNRBC and the placental injury. Meanwhile, the expre- ssion of FAS and VEGF protein in placenta is regarded as quantitative indicators of pla- cental injuries, so as to explore a method to diagnose placental injuries during pregnan- cy.By means of single density gradient centrifugation, 180 cases of maternal blood samples were enriched, and then the FNRBC was stained by Wright staining and counted. The statistical result revealed that the number of FNRBC was in skew distribution. Taking P80 (80percentage) as the criterion to distinguish the abnormality and the normality, the normal number of FNRBC is less than 8/ml. Of FNRBC abnormal placenta of 30 cases of pregnant women were tracked, at the same time, 10 controls were randomly selected from the pregnant women with the normal number of FNRBC. All of them were stained with H&E to observe the morphological changes of placenta. It was discovered that the 10 cases with the normal number of FNRBC were the normal pregnancy placenta. In the 30 cases of pregnant placentas containing abnormal number of FNRBC, it was found that there were 17 placentas with mild injuries and 13 placentas with severe injuries. The results indicated that the number of FNRBC in maternal blood was relevant to placental injuries.Because morphological changes of placental injuries is difficult to be quantized, FAS factor associated with apoptosis and vascular endothelial growth factor (VEGF) were selected to quantify the indicators of the degree of placental injuries, and they were regarded as the intermediary of relationship between FNRBC and placental injuries. FAS and VEGF in placenta detected by immunohistochemical techniques were used to analyze the relation between FAS, VEGF and the placental injury. The result showed that FAS and VEGF were associated with the placental injury. By further investigating the relation among FNRBC, FAS and VEGF, it could be found that the number of FNRBC was positively correlated with FAS expression in placenta, and was negatively correlated with the VEGF expression in placenta.The results of the study indicated: There is correlation between the number of FNRBC in maternal blood and severity of placental injuries. Therefore, the number of the FNRBC during pregnancy may be taken as an indirect indicator to assess the extent of placental injuries.