الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 76 |  |  |
| | | from | 76 | | |
Abstract
Placenta previa exists when the placenta is inserted into the lower uterine segment and covers partially or entirely the cervix.
The term morbidly adherent placenta implies an abnormal implantation of the placenta into the uterine wall and has been used to describe placenta accreta, increta, and percreta.
The overall incidence of placenta accreta is around 3 per 1000 deliveries, and there has been a considerable increase in the incidence of placenta accreta over the past several decades.
The presence of a prior caesarean delivery in a patient significantly increased the risk of placenta accreta, especially in association with the presence of placenta previa.
The pathogenesis of placenta accreta is not clear however, there have been several theories proposed. Abnormal vascularization resulting from the scarring process after surgery with secondary localized hypoxia leading to both defective decidualization and excessive trophoblastic invasion appears to the most supported theory.
Placental development requires the coordination of angiogenic growth factors and their receptors. These protein factors include vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and their receptors.
The aim of this study to evaluate the effectiveness of ultrasound as screening tool of placenta accreta in cases of previous caesarean deliveries and low lying anterior placenta in the first trimester and clarify the relation between PlGF and placenta accreta.
The study was carried out at the obstetric clinic and ultrasound unit for antenatal care in El-Shatby Maternity University Hospital on 80 singleton pregnant women with a case: control ratio 1:1 from December 2015 to June 2017.All patients had ultrasound examination by trans-abdominal and trans-vaginal routes during first visit at 11-14 weeks and second visit at 24-32 weeks of gestation, Blood sample was taken for measuring of Serum placental growth factor by enzyme-linked immunosorbent assay at 11-14 week of gestation.