A young Chinese couple who were both diagnosed with a rare autoimmune disorder a year after getting married have lost their newborn baby.

The couple in northern China’s Tianjin municipality were diagnosed with Bickerstaff brainstem encephalitis last year.

The husband, surnamed Li, said only four couples in the world had been diagnosed with the disorder at the same time, and they were the first case in China.

Li, 32, had a fever last March, a year after he married his wife. He also felt generally weak, his vision was blurry and his limbs were numb.

He was misdiagnosed as having a stroke at a hospital, and received the wrong treatment. When he received the correct diagnosis, it was too late and he was left paralysed.

Two months after Li’s diagnosis, his wife, Zhao, who was six months pregnant, also developed the same symptoms.

Still hoping the baby would be fine, she still delivered him prematurely soon after the diagnosis, but the newborn died shortly after birth.