Risk factors for vertical transmission of hepatitis E virus infection.

Hepatitis E virus (HEV) infection can be vertically transmitted, but the factors that transmit the disease to foetuses are still unclear. We studied a total of 144 pregnant women with HEV infection. Cord blood and newborn samples were taken for analysis. Nutritional factors were evaluated on the basis of anthropometric parameters and biochemical factors, and HEV viral load was quantified by real-time PCR. Sequencing of HEV-positive samples was performed. Approximately 14.63% (6/41) of pregnant patients with acute liver failure (ALF) died before delivery. Vertical transmission was observed in 46.09% (59/128) of HEV-IgM-positive mothers. Approximately 23.80% (10/42) of newborns in the acute viral hepatitis group and 29.41% (5/17) in the ALF group were positive for HEV-RNA. No significant difference was observed in the occurrence of vertical transmission in HEV groups. Viral load was found to be a significant predictor for vertical transmission of HEV infection adjusted with haemoglobin and folate in derivation cohort group. Incorporating these variables, a new score predicting vertical transmission of HEV was derived. Using these significant predictors, the probability for vertical transmission of HEV was well stratified in the validation group (P>.05). In conclusion, viral load was associated with vertical transmission of HEV infection. A valid prediction score model was generated that was verified in a validation cohort group.