Anterior uterine incarceration complicated by placenta previa and placenta accreta spectrum disorder: a case report

Background: Uterine incarceration is a rare obstetric complication that is always associated with retroversion and prone to misdiagnosis. Pelvic examination and imaging methods including ultrasound and magnetic resonance imaging (MRI) are used as the primary diagnostic tool. We present an asymptomatic anterior uterine incarceration complicated by placenta previa and placenta accreta spectrum (PAS) disorder, which could be diagnosed during the pregnancy periods, but was first diagnosed during the cesarean section (CS) and got the surgeons into trouble.Case Description: A 28-year-old woman, gravidity 4, parity 1, was hospitalized due to placenta previa and PAS disorder diagnosed by ultrasound and MRI at 35.6 weeks of gestation. She had not experienced any discomfort. Given her history of a previous CS, she underwent a well-prepared cesarean delivery for the termination of the pregnancy. The patient had a series of periodical ultrasound and MRI examinations in which placenta previa and placenta accreta were described in disregard of the abnormal location of cervix; consequently, interior uterine incarceration was first diagnosed during the surgery, which caused significant difficulties in the operation which lasted 3 hours and 21 minutes. The patient developed severe hemorrhaging and lost approximately 5,000 mL of blood. Fortunately, she delivered a health male infant weighing 3,440 grams with quite good Apgar scores. During the follow-up, maternal and child health was confirmed.Conclusions: With regard to patients who have undergone previous pelvic surgery, doctors need to pay close attention to the position of the cervix, the pelvic adhesion situation during the prenatal examination, and be on alert for uterine incarceration. Uterine incarceration can be accurately recognized by periodic sonography and MRI if the radiologist is aware of this unusual condition. We do suggest that special are must be taken to avoid unnecessary trauma by misdiagnosis because of lack of awareness.