Successful Management of Complicated Uterine Displacement Caused by Unilateral Incarceration of the Bicornuate Uterus

Uterine incarceration is a serious complication of pregnancy, in which the gravid uterus becomes trapped in the posterior pelvis. When labor occurs, delivery does not progress, and the uterus may rupture. Therefore, preoperative diagnosis of uterine incarceration is important, and a caesarian section is indispensable except when the polarity of the uterus can be successfully restored. We report the case of a 35-year-old primipara with a complication of a bicornuate uterus who became pregnant after in vitro fertilization and embryo transfer. No abnormality was observed on regular checkups until the second trimester. At 28 weeks' gestation, the uterine cervix revealed marked dislocation, and, at 31 weeks, magnetic resonance imaging (MRI) revealed uterine cervix elongation and left horn incarceration. At 37 weeks' gestation, an elective cesarean section was performed. On laparotomy, the uterus was found to be markedly dislocated, and distended blood vessels were observed on the surface. Ultrasound examination was performed directly on the uterine wall to decide the incision site. After delivery of the baby, manual repositioning of the uterus revealed the unique concurrent clockwise rotation and retro-vertical deflection. Thus, we concluded that incarceration accompanied by a bicornuate uterus can cause complicated uterine displacement, and preoperative MRI and intraoperative ultrasound examination are useful for managing this condition.