Which of the following is the most common cause of fulminant hepatic failure in pregnancy?

Hepatitis E virus cause fulminant hepatic failure in pregnant women. Maternal moality associated with this condition occur at a rate of 25%. Hepatitis E virus is a single stranded RNA virus. Incubation period is 45 days. It is spread through feco-oral route. It is endemic in developing countries of the world. It does not cause chronic carrier state. Ref: Management of High-Risk Pregnancy : An Evidence-Based Approach By John T. Queenan, 5th Edition, Page 238-9 ; Principles of Gender-Specific Medicine, Volume 1 By Marianne J. Legato, 2nd Edition, Page 334