BACKGROUND: In the Netherlands, different hepatitis B vaccination schedules have been used for children born to HBV-infected mothers. All schedules included a birth dose of hepatitis B immunoglobuline (HBIg). We assessed determinants of perinatal HBV transmission and determinants of anti-HBs titers in infants born to HBsAg positive mothers. METHODS: We included infants born to HBV infected mothers between 1.1.2003 and 30.6.2007, using national databases and a separate database for Amsterdam. Risk factors for perinatal transmission and determinants of the anti-HBs titer were studied using logistic and linear regression, respectively. RESULTS: Of 2657 infants registered in the national database, 91% were registered to have received HBIg and at least three hepatitis B vaccinations. In Amsterdam, this coverage among 413 children at risk was higher (96%, p<0.01). Serological test results for 2121 infants (80%) indicated that 13 (0.6%) were HBsAg positive. A mother of Chinese descent was the only risk factor for perinatal HBV infection identified (RR 9.1, 95% CI 3.1-26.8). Receiving a birth dose of hepatitis B vaccine later than in the first week of life was not associated with an increased risk of perinatal HBV infection. A shorter period between last vaccination and testing, and having received more doses of hepatitis B vaccine were independently associated with a higher anti-HBs titer. CONCLUSIONS: Infants born to Chinese mothers were at increased risk of perinatal HBV infection. All HBsAg positive pregnant women of Chinese origin should be assessed to determine whether there is an indication for anti-viral treatment during pregnancy. Among infants who received HBIg at birth, we did not detect an increased risk of perinatal HBV infection when the first dose of hepatitis B vaccine was administered after the first week of life.
BACKGROUND: In the Netherlands, different hepatitis B vaccination schedules have been used for children born to HBV-infected mothers. All schedules included a birth dose of hepatitis B immunoglobuline (HBIg). We assessed determinants of perinatal HBV transmission and determinants of anti-HBs titers in infants born to HBsAg positive mothers. METHODS: We included infantsborn to HBV infected mothers between 1.1.2003 and 30.6.2007, using national databases and a separate database for Amsterdam. Risk factors for perinatal transmission and determinants of the anti-HBs titer were studied using logistic and linear regression, respectively. RESULTS: Of 2657 infants registered in the national database, 91% were registered to have received HBIg and at least three hepatitis B vaccinations. In Amsterdam, this coverage among 413 children at risk was higher (96%, p<0.01). Serological test results for 2121 infants (80%) indicated that 13 (0.6%) were HBsAg positive. A mother of Chinese descent was the only risk factor for perinatal HBV infection identified (RR 9.1, 95% CI 3.1-26.8). Receiving a birth dose of hepatitis B vaccine later than in the first week of life was not associated with an increased risk of perinatal HBV infection. A shorter period between last vaccination and testing, and having received more doses of hepatitis B vaccine were independently associated with a higher anti-HBs titer. CONCLUSIONS:Infants born to Chinese mothers were at increased risk of perinatal HBV infection. All HBsAg positive pregnant women of Chinese origin should be assessed to determine whether there is an indication for anti-viral treatment during pregnancy. Among infants who received HBIg at birth, we did not detect an increased risk of perinatal HBV infection when the first dose of hepatitis B vaccine was administered after the first week of life.