Fig. 1

Blood supply to the acardiac twin and conjoined area. Note: (a) The blood supply to the acardiac twin originates from a branch of the pump twin’s aortic arch; (b) Vessels near the attachment site of the pump twin’s umbilical cord; (c) The conjoined area between the acardiac twin and the pump twin, with the connection area highlighted. The images were obtained using two-dimensional ultrasound, showing the vascular anastomosis and the conjoined fetal structures