Hepatitis E is a severe, acute disease caused by the Hepatitis E Virus (HEV). It can lead to severe liver damage. In most patients, however, it normally 'self resolves' (there is no specific effective treatment). It's widespread across the world, and is currently estimated to be responsible for around 77,000 deaths per year.

The mortality rate is estimated at 0.2% to 1% - but, in pregnant women this jumps to around 30%. There is currently no explanation for this very significant increase in mortality.

The mechanisms of severe liver injury due to HEV infection in pregnant women are unknown. According to previous studies, the unique characteristics of pregnant women, such as altered immunity, hormone levels, and viral factors, such as HEV genome heterogeneity and variants, may be related to the severity of the disease.

Source : Virology Journal volume 17, Article number: 73 (2020)