 Later in the year, when Empress Yujiulü herself was about to give birth, she heard unusual barking noises in the palace, and she suspected them as from the spirit of Empress Yifu.She therefore grew depressed, and she died either during or shortly after childbirth in 540.Eastern Wei regent Gao Huan skillfully used this opportunity, sent Zhang Weiquan, who transmitted a letter to the Khagan.