الفهرس 
Epidemiology and Pathophysiology of Morbidly Adherent Placenta (MAP)Only 14 pages are availabe for public view
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Abstract
Abnormal attachment of the placenta occurs when all or part of the placenta attaches abnormally to the myometrium. Recently the term, morbidly adherent placenta (MAP), has been more frequently used to describe abnormal implantation of the placental villi into the uterine wall. MAPs are further classified as accrete (adherence into myometrium), increta (invading into myometrium), or percreta (invading through myometrium).Both a history of cesarean delivery and placenta previa are known risk factors for MAP.
The incidence of MAP has continued to rise, primarily because of the increase in cesarean delivery rates, with overall incidence of approximately 1 in 500 pregnancies.
MAP can result in major maternal morbidities such as life-threatening hemorrhage and intra-operative organ injuries. Therefore, it is important to be able to detect this entity antenatally with high reliability to allow for proper preparation for delivery in an appropriate unit equipped to handle potentially complicated surgery.
The diagnosis of MAP has traditionally been suspected on 2-dimensional (2D) ultrasound:
• The presence of hypo echoic areas in the body of the placenta (placental lacunae).
• The loss of the normal hypo echoic myometrium adjacent to the base of the placenta (loss of sonolucency).
• Absent or disrupted hyper echoic line separating the uterus from the urinary bladder (abnormal uterine serosa-bladder line).
They have all been identified as markers of MAP on 2D ultrasound. Although how the color Doppler findings should be used is subjective and the published descriptions of exactly what findings are predictive of MAP are not specific, color Doppler of vascular patterns in the placenta and magnetic resonance imaging (MRI) may also be helpful in establishing the diagnosis.
Despite these reported findings, the diagnosis of MAP remains as a subjective diagnosis per the interpretation of the observer. Additionally, there is limited previously published studies available for 2D to determine the severe form of MAP that is associated with massive hemorrhage, percreta or increta, and intensive care admission.
This prospective cohort study was conducted at Ain Shams University Maternity Hospital at the department of Obstetrics and Gynecology in the period from September 2018 to September 2019.
The population of this study was 100 pregnant women with placenta previa women who were referred to the ultrasound unit for the evaluation of placenta previa and morbidly adherent placenta between 28 and 32 weeks of gestation who were admitted to Ain Shams University Maternity Hospital and planned for elective lower segment cesarean section and were allocated in 2 groups after delivery:
group (A): patients without MAP.
group (B): patients with MAP confirmed by histopathological examination of hysterectomy specimen and according to this examination they will be sub grouped into MAP and severe MAP.
Women with fetal anomalies and multiple gestations were excluded from our study.
Combination of transabdominal and transvaginal ultrasound was performed to confirm the location of placenta using routine 2D imaging.
The uniform diagnostic criteria were applied to diagnose the suspected MAP, then if one of these criteria was found the pregnant women underwent additional imaging using 3D power Doppler transabdominal ultrasound of the placenta after confirming full bladder. The placental images were optimized for every patient to visualize the maximum placenta with the suspected MAP at the center of the imaging area. The 3D placental volume was obtained by imaging the placenta sagittally. Histogram analysis was applied to the taken images. The 3D placental volumes were assessed by manual tracing at 30⁰ angle increments to include the maximum viewed placenta. The volume of the placenta was documented. The vascularization index (VI), the flow index (FI) and the vascular flow index (VFI) were calculated using the same software. Once the placenta was traced and histogram analysis was applied, results were obtained.
Our results showed that the 3D color Doppler VI ≥ 16 predicted the diagnosis of MAP with a 100% sensitivity , 100% specificity which are better than those of 2D ultrasound (60.0% and 89.1% respectively).
Severe MAP occurred in 51.2% of MAP and 3D color Doppler of VI > 33.1 predicted severe MAP with a sensitivity of 73.9% and specificity of 86.4%, which was superior to 2D ultrasound.
In the current study the sensitivity and the specificity of 2D ultrasound for the diagnosis of MAP was 60.0% and 89.1% respectively when at least one abnormal parameter was present. The sensitivity and specificity dropped to 69.6% and50.0% respectively when severee MAP was the outcome.