Background:  Vertical transmission of hepatitis B virus (HBV) is known to be the most common cause of peri-natal infection.

The purpose of the work: To demonstrate the prevalence, possible risk factors of HBV infection among pregnant women in Upper Egypt, and target women for post partum immunization.

Patients and methods: 294 pregnant Egyptian women were consecutively recruited from outpatients' clinic of women health care centre of Assiut University hospital. Clinical evaluation and questionnaire about risk factors for HBV transmission were done. Blood samples were tested for HBsAg, Anti-HBs, and Anti-HBc. Positive samples for HBsAg were tested for HBeAg and quantitative PCR for HBV. Newborns of HBsAg positive mothers were tested for HBsAg immediately after labour and 9 months later. Passive-active immunization was given to newborns of HBsAg positive mothers. 

Results: The prevalence of HBsAg among pregnant women was 4.8 %. Target women for postpartum vaccination were 82.3 % (those with negative Anti-HBs).  PCR for HBV was positive in 50 % of HBsAg positive pregnant women. None of the newborns of infected mothers were positive for HBsAg at birth and after 9 months. Previous blood transfusion, HBV infection in the family, and family history of liver disease were significant predictive factors for HBV infection in univariate analysis among Egyptian pregnant women. HBV infection in the family was the only independent predictor for HBV infection among pregnant women.

 Conclusions: There is intermediate prevalence (4.8 %) of HBV infection among Upper Egyptian pregnant women. Family history of HBV infection is the only independent risk factor for HBV infection among pregnant women. Passive-active immunization to newborns of infected mothers resulted in 100% reduction of peri-natal HBV infection.