Imaging findings of concealed intra-amniotic hemorrhage in the setting of placenta previa and placenta accreta spectrum disorder.

Placental abruption is an important cause of feto-maternal hemorrhage, with significant impact on both fetal and maternal mortality. In most cases, it presents with abdominal pain and vaginal bleeding. However, vaginal bleeding may be absent with concealed intra-amniotic hemorrhage, as in cases with placenta previa, hence confounding this diagnosis. In such cases, imaging studies may be obtained to evaluate for abdominal pain in pregnancy; hence, radiologists should be aware of the ultrasound and magnetic resonance (MR) imaging appearance of intra-amniotic hemorrhage. This includes presence of markedly echogenic amniotic fluid on US. Hemorrhage signal intensity on MR imaging varies with the duration of bleeding. In acute to subacute cases, it will present as T1 isointense and T2 hypointense amniotic fluid. This case is the first report of MR imaging findings of acute concealed intra-amniotic hemorrhage.