A First Trimester Scan may Reveal the Presence of Placenta Accreta. Absence of the Anterior Uterine Wall During Caesarean Section: An Unexpected Placenta Accreta that was Treated Conservatively

Objective. Placenta accreta spectrum (PAS) is a rare condition, but it is a potential life threating obstetric event. Case report. A second-time mother, 32 years old, has had a caesarean section before. At 11 weeks, a doubt about scar pregnancy was posed but not confirmed at subsequent serial ultrasound evaluations. A caesarean section was performed at 38.4 weeks for breech presentation. A placenta accreta, diagnosed during surgery and confirmed by histological evaluations, was visible at uterine examination with a lacuna in the anterior uterine wall. After fetal extraction, the surgeons opted for conservative management. Subsequent clinical and ultrasound follow-up described a patient in a good state of health with a progressively reduced intrauterine placenta residual. Conclusions. (1) Even in the absence of typical second- or third-trimester ultrasound signs, first trimester ultrasound played a role in posing the suspect of PAS. (2) Conservative management could be a safe option in cases of undiagnosed PAS, even if reported in the literature as a correlation with possible subsequent complications, which must be explained to the patient with adequate counseling.