Placenta accreta in the first trimester of pregnancy: sonographic findings.

In a case of histologically confirmed placenta increta, decidual protrusion into the myometrium was observed sonographically at 6 weeks' gestation, corresponding to placental protrusion from a disrupted placental-uterine wall interface seen in the later part of the first and second trimester. It is hypothesized that the histologic finding of decidual scarcity in placenta accreta is not a cause but rather an end result of the recruitment of trophoblasts across the decidual-placental interface in a maternal attempt at healing and/or repair in the presence of uterine injury, disease, or malformation that accounts for the associated factors and course of the condition.