الفهرس 
PlacentaOnly 14 pages are availabe for public view
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Abstract
Placenta accreta was first described in 1937 by Irving& Hertig as failure of separation of the placenta from the uterine wall following delivery of the human fetus due to abnormal adherence of the placental trophoblast to the uterine myometrium leading to the often used term morbid adherent placenta (17).
The condition is characterized by abnormal invasive placentation which is associated with catastrophic hemorrhage. Varied terminology has been applied to this condition; however, recent guidelines suggested that placenta accreta spectrum PAS, which includes accreta, increta, and percreta, condition is unique to human pregnancy with no animal correlate reported (18).
Accurate antenatal diagnosis of an abnormally invasive placenta (AIP), allowing multidisciplinary management at the time of delivery, has been shown to improve maternal and fetal outcomes (83).
Abnormally invasive placenta can be predicted as early as in the first trimester, and almost always confirmed in the second and third trimesters via Grayscale ultrasonography, with or without color Doppler has been used widely for antenatal screening and diagnosis of AIP (49).
This study aimed to evaluate the sensitivity and specificity of each ultrasound criterion comparing them with the final outcome of pregnancy and assessment of placental invasion in cases of placenta previa anterior wall with previous uterine scar specifically showed the role of uterine artery Doppler in diagnosis of placenta accrete in patients with placenta previa.
Our study was prospective diagnostic accuracy cohort study and was conducted on (60) pregnant women diagnosed as placenta previa by ultrasound and were candidates for either emergency or elective repeated CS or hysterectomy (if diagnosis of placenta accreta is confirmed). 6 patients were excluded as they leave hospital, 32 patients were diagnosed as placenta accrete 8 did hysterectomy and 24had conservative management, 22 patients were diagnosed as placenta previa with no accretion.
All patients had ultrasound examination (2D gray scale and color Doppler) via transabdominal and transvaginal approach to Confirm the presence of placenta previa or low-lying placenta, to assess the possibility of concomitant placenta accreta (Sonographic findings that have been associated with placenta accrete like:loss of normal hypoechoic retroplacental zone, multiple vascular lacunae within placenta, giving ―Swiss cheese‖ appearance, blood vessels or placental tissue bridging uterine-placental margin, myometrial-bladder interface, or crossing uterine serosa, myometrial thickness of 1 mm, bladder wall interruption, presence of placental bulge, utero-vesical hypervascularity, assessment of the adjacent structures that may be invaded by placenta percreta, assessment of uterine artery Doppler in different cases of placenta previa transabdominally.
The transabdominal approach is by identifying the right and left uterine arteries at the apparent crossover with the external iliac arteries.
As regard the accuracy of 2D ultrasound parameter for diagnosis of placenta accreta, absence of sonolucent areas, sensitivity was 94%, specificity 91%, PPV94%
SUMMARY
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and NPV 91%,Myometrial thickness less than 1mm, sensitivity was 66%, specificity 95, PPV 95% and NPV 66%,number of lacunae more than 2 sensitivity 88%, specificity 55, PPV 74% and NPV 75%.
As regard the accuracy of PI of uterine artery Doppler for prediction of placenta accreta, sensitivity was 78%, specificity was 91%, PPV was 93% and NPV was 74%.
Our study showed that loss of retroplacental space is the most accurate ultrasound parameter in diagnosis of placenta accrete.
Although there is statistically significant value of uterine artery Doppler indices were observed during this study when placenta accreta cases were compared to non accreta cases,it should not be used as a single ultrasonographic parameter in diagnosis of placenta accrete.