Kinetics of hepatitis B surface antigen in pregnant women with and without tenofovir disoproxil fumarate.

Abstract

Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent mother-to-infant transmission in highly viremic HBV-infected women. Data on hepatitis B surface antigen (HBsAg) levels in pregnant women are lacking. We aimed to investigate prepartum and postpartum HBsAg kinetics and its correlation with HBV DNA in pregnant women. HBV-infected mothers with HBV DNA ≥7.5log10 IU/ml were tested for HBsAg and HBV DNA from baseline to 6months postpartum. Of the 186 pregnant women with comparable baseline HBsAg and HBV DNA, 101 received TDF from the third trimester until 1month postpartum. At delivery, TDF group had mildly lower HBsAg (4.32±0.47 vs. 4.54±0.35log10 IU/ml, p=.0004) and markedly lower HBV DNA (4.26±0.97 vs. 8.11±0.70log10 IU/ml, p<.0001) than the control group. In the TDF group, mean reduction of HBsAg and HBV DNA from baseline to delivery were 0.22±0.38 and 3.96±0.93log10 IU/ml. HBsAg reduction had a positive correlation (r=.309; p=.0017) with HBV DNA reduction, and was predictive of HBV DNA reduction ≥3log10 IU/ml (area under the receiver operating characteristic curve, 0.67; 95% confidence interval, 0.50-0.82). At 6months postpartum, TDF and control group had comparable HBsAg and HBV DNA. In conclusion, HBsAg decreased slightly at delivery in pregnant women receiving TDF. For monitoring the effect of antiviral therapy during pregnancy, HBV DNA is a better marker than HBsAg. Our data provided valuable information regarding monitoring HBV-infected pregnant women using antiviral therapy.