Virological Determinants of Spontaneous Postpartum e Antigen Seroconversion and Surface Antigen Seroclearance in Pregnant Women Infected with Hepatitis B Virus.

BACKGROUND AND AIMS: We investigated the virological factors predicting spontaneous postpartum hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) seroclearance in pregnant women infected with hepatitis B virus (HBV).

METHODS: We invited 419 HBV infected women whose sera had been collected during their pregnancy from August 2002-July 2004 and archived at -30°C, to participate the follow-up in October 2009-March 2010. Various virological factors were determined and compared in women with or without the seroconversion and seroclearance.

RESULTS: A total of 264 (63.0%) antiviral naive women participated in the follow-up with an average observation period of 6.4 years (5.4-7.4). Of 76 women who were HBeAg positive during pregnancy, 42 (55.3%) seroconverted to anti-HBe during follow-up. Compared to pregnant women with HBV DNA ≥3 × 10(7) IU/mL or HBeAg ≥770 S/CO, those with HBV DNA <3 × 10(7) IU/mL or HBeAg <770 S/CO had higher conversion rate, with odds ratios (OR) of 7.32 (95% confidence interval [CI], 2.00-26.78) and 5.94 (95% CI, 1.40-25.16), respectively. Thirty eight (14.4%) women cleared HBsAg; pregnant women with HBsAg levels of 100-999 and <100 IU/mL had higher HBsAg seroclearance rate with OR of 2.58 (95% CI, 1.03-6.43) and 13.33 (95% CI, 5.07-35.07), respectively, compared to those with HBsAg >1000 IU/mL.

CONCLUSIONS: HBeAg-positive pregnant women with HBV DNA <3 × 10(7) IU/mL or HBeAg <770 S/CO are more likely to undergo postpartum HBeAg seroconversion. HBsAg <100 IU/mL is a strong predictor of spontaneous postpartum HBsAg seroclearance.