Placenta Accreta: A Spectrum of Predictable Risk, Diagnosis, and Morbidity

Objective   Placenta accretais a feared pathology, in part, because prenatal diagnosis is imperfect. It is not known whether clinical risk factors or sonographicfeatures equally predict the entire graded pathological spectrum of placental overinvasion disease nor whether clinical outcomes differ along the spectrum. Study Design  We conducted a mixed methods retrospective study of a cohort of women screened sonographicallyfor placenta accreta, cross-referenced against cases identified by pathological diagnosis ( N  = 416). Demographic, diagnostic, and outcome information were compared across the spectrum of invasive placentation: percreta, increta, accreta, and focal accreta not requiring hysterectomy. The t -test, chi-square, Mann–Whitney, and Kruskal–Wallis tests were used for statistical analysis across groups. Results  As the depth of invasion decreased, risk factors for placental overinvasion were less common, especially placenta previaand previous cesarean. There was also reduced anticipation by sonographicexamination of the placenta. Rates of adverse outcomes were lower among women with focal accreta compared with those with deeper invasion. Conclusion  As the depth of invasion decreases, clinical risk factors and sonographicevaluation are less reliable in the antenatal prediction of placenta accreta. The potential for unanticipated morbidity underscores the need for improved diagnostic tools for placenta accretaspectrum.