الفهرس 
Placenta previa and accretaOnly 14 pages are availabe for public view
Abstract
I
mplantation requires decidualization and vascular remodeling to provide essential nutrients and substrates to embryo. Some pregnancy complications such as early pregnancy loss, ischemic placental diseases, preeclampsia, intrauterine fetal growth restriction and premature delivery result from disturbed vascular growth in the placenta.
Invasive nature of trophoblasts requires a strict control for healthy placentation.
Highly invasive nature of trophoblastic tissue may result in abnormal attachments to the uterine wall and therefore trophoblasts may invade into the myometrium.
The development of PAS is a complex multifactorial process. Normal placentae do not proceed beyond the inner third of the myometrium through tight spatial and temporal regulation; however, an invasive placenta proliferates and invades local structures in a similar fashion to a malignant tumour. The underlying molecular mechanisms of invasive placentation are poorly understood; proposed hypotheses include a combination of primary absence of the decidua or basal plate, abnormal maternal vascular remodelling, and excessive extravillous trophoblastic invasion.
Improved understanding of the molecular basis of other placental disorders such as preeclampsia suggests the inflammation and placental invasion may be closely related. A number of comparisons can be drawn between the microenvironment of PAS and tumour behaviour. Both conditions require an ability of cells to overcome the local immunological systems, activate invasion, and induce angiogenesis. In 2012, Hanahan and Weinberg outlined eight hallmark capabilities of tumours which allow them to invade and metastasise. Herein, we use these eight hallmarks of cancer to highlight some of the molecular similarities between PAS and tumour development.
• Inducing Angiogenesis.
• Sustained Proliferative Signalling.
• Resisting Cell Death.
• Evading Immune Destruction.
• Activating Invasion.
• Enabling Replicative Immortality/Evasion of Growth Suppression.
• Reprogramming of Energy Metabolism.
In women with a history of prior CD, scar defects are found to range between 20-65% of the myometrium after delivery on transvaginal ultrasound. Women with a residual myometrial thickness of <50% of the adjacent myometrium are more likely to develop chronic complications such as intermenstrual spotting.
The myometrial fibers around a scar often show hyalinization or degenerative changes, with a local increase in fibrous tissue and infiltration by inflammatory cells. The comparison of ultrasound features of uterine cesarean scar with histological findings has shown that large and deep myometrial defects are often associated with absence of reepithelialization of the scar area.
Leukocytes recruitment to the endometrium during the secretory phase may also be affected by the presence of a CD scar. A recent study of the uterine circulation in women with a previous CD has shown that the uterine vascular resistance is increased, while the volume blood flow is decreased, compared to women with a previous vaginal birth.
These data suggest that the blood circulation around the scar is impaired. Poor vascularization of the scar area may lead or contribute to permanent focal myometrial degeneration, as well as reduced or absent reepithelialization of the scar area.
Numerous studies proposed that cancer cell invasion has several common features with the trophoblast invasion.
The neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios are recent popular markers for inflammatory response and have been successfully applied as predictive markers and prognostic factors in variousgynecological cancers.
Due to the similarity with the cancer cell invasion and evidence for the predictive value of complete blood count parameters for several cancer types. So, in this study we try to assess the relationship between some parameters of complete blood count and placental invasion anomalies.
The main object was presence of significant differences between groups with and without placental invasion anomaly in terms of neutrophil, platelet count, mean platelet volume, red cell distribution width and neutrophil to lymphocyte ratio.
In our study, we tried to assess the predictive value of some complete blood count parameters for placental invasion anomalies that were shown to be significant indicators for several malignancies. Study indicated some pathophysiological similarities between tumor and placental trophoblastic invasion. Researches on the trophoblasts revealed similarities between the proliferative, migratory and invasive properties of placental cells and those of cancer cells.
Our results found that mean platelet volume (MPV) (P=<0.001) and neutrophil/ lymphocyte (N/L) ratio (P=<0.001) were significantly higher in cases with placenta accreta. Red blood cell distribution width (RDW) (P=<0.001) and platelets count (P= 0, 004) were significantly lower in cases with placenta accreta.
Only red blood cell distribution width (RDW), platelets count, mean platelet volume (MPV) and neutrophil/ lymphocyte (N/L) ratio had significant diagnostic performance in diagnosing placenta accrete and mean platelet volume MPV ≥8.1 (fL) had highest diagnostic characteristics in diagnosing placenta accreta.
In our study, MPV and P-LCR values were significantly higher. Diminution of platelet counts and simultaneous enhance¬ment of their volume and distribution width over the third trimester might be caused by their destruction, regarding microangiopathic reasons, even in a normal pregnancy.
Conclusion
There are changes in CBC parameters which can predict placental invasion anomalies such as increase in Mean platelet Volume(MPV), Neutrophil / lymphocyte (N/L) ratio and decrease in Red cell Distribution Width (RDW), Platelet’s count.
The cut point’s in predicting placenta accreta by complete blood count are.
1) Mean platelet Volume(MPV) ≥ 8,1fl had the highest diagnostic characteristics.
2) Neutrophil / lymphocyte (N/L) ratio ≥4.1.
3) Red cell Distribution Width (RDW) ≤ 16.6%.
4) Platelet’s count ≤ 264.0(x103/mL).
Recommendations
In suspected cases of placenta accrete by ultrasound, We recommend to evaluate every change in CBC parameters which can predict placental invasion anomalies eg. Mean platelet Volume (MPV), Neutrophil / lymphocyte (N/L) ratio and Red cell Distribution Width (RDW), Platelet’s count