Sonographic Features in the Placenta Accreta Spectrum

Background: Abnormally invasive placenta is defined as abnormal adhesion to the implantation site, it is a spectrum of abnormal placentation that leads to obstetric hemorrhage, knowledge of risk factors and ultrasound evaluation is what allows antenatal diagnosis allowing transfer to specialized centers, surgical planning, and modifying the maternal outcome, causing a decrease in maternal morbidity and mortality. Objective: To describe the main ultrasound signs found in patients diagnosed with abnormally invasive placenta. Methodology: Cross-sectional, descriptive, retrospective study, carried out through a bibliographic review in the databases of PubMed, Scholar.google.com, SciELO, MEDLINE, of articles published in English and Spanish between 1992 and 2020. The following methods were used. Keywords Mesh (Medical Subject Headings): placenta accreta; previous placenta; prenatal diagnosis; abnormally invasive placenta; placenta percreta; abnormally attached placenta. Inclusion criteria: case report-type articles that include pregnant patients with placenta accreta, associated risk factors and diagnostic evaluation sections, as well as a systematic review and meta-analysis on the prenatal diagnosis of placenta accreta, whose results were analyzed by analysis of frequency. Results: From the reviewed studies, it was observed that 66.7% of the patients had cesarean section as the predominant uterine surgery, ultrasound findings such as the loss of the hypoechoic zone in 35.7% of the cases; the presence of placental lacunae in 28.6%; myometrial thinning in 16.7%; as well as disruption of the uterus-bladder interface in 7.1%, in 54.8% intraoperative diagnosis was made. Conclusions: Placental accreta is an increasingly frequent pathology, the incessant search for alternatives to reduce maternal death, the ultrasound characterization of the most frequent signs help timely prenatal detection