Case report of a maternal urinary bladder asymmetry in a twin gravid bicornuate uterus.

Twin gestation in a bicornuate uterus, where each fetus occupies a separate horn, is a rare event. Our case is about a 32-year-old woman with twin gestation at 33weeks who was admitted to our hospital because of premature labor symptoms. After 16 h from admission a cesarean section was performed and we found that the dimension of the two uterine horns was equivalent but the vesicouterine fold of the right horn was 4 cm above the contralateral one. The creation of the bladder flap was particularly challenging because of its atypical conformation in the gap between the two uterine horns. Even thought the entire bladder walls were thoroughly inspected, we decided to intraoperatively test the integrity by filling the bladder with a solution of sterile water and methylene blue. Blue dye spilled out into the operative field.The identified laceration was closed. Our case suggests that intraoperative testing of bladder integrity in bicornuate uterus can be considered also when the visual inspection of the bladder excludes macroscopic injuries.