# Higher risk of postpartum phase transition to immune-active among HBeAg-positive pregnant women with indeterminate phase

## TL;DR

This study shows that HBeAg-positive pregnant women in the indeterminate phase are more likely to transition to an immune-active phase after childbirth, highlighting the need for close postpartum monitoring.

## Contribution

The study reveals new insights into how pregnancy affects HBV infection dynamics, particularly in HBeAg-positive women in the indeterminate phase.

## Key findings

- HBeAg-positive pregnant women in the immune tolerance phase showed a higher risk of transitioning to the immune-active phase postpartum.
- The immune tolerance phase was most common in the third trimester, followed by the indeterminate and immune-active phases.
- Postpartum liver disease progression was low across all disease phases in pregnant women with CHB.

## Abstract

Understanding the natural history of hepatitis B virus (HBV) infection helps determine the optimal timing of antiviral therapy. However, a gap exists in the literature regarding the dynamics of the natural history of HBV infection in pregnant women with chronic hepatitis B (CHB). This study aimed to explore the natural history of HBV infection during pregnancy and the postpartum period.

We conducted a retrospective–prospective real-world study involving 276 pregnant women with CHB. Infection dynamics during pregnancy were characterized in 228 hepatitis B e-antigen (HBeAg)-positive and 48 HBeAg-negative participants, respectively, and during postpartum follow-up in 108 HBeAg-positive and 21 HBeAg-negative participants. HBeAg-positive participants received short-term antiviral intervention according to current guidelines. Liver disease progression was also evaluated.

Throughout pregnancy, the proportion of patients in the immune tolerance (IT) phase increased progressively, whereas the proportions of patients in the HBeAg-positive indeterminate phase (IP) and HBeAg-positive immune-active (IA) phase decreased. In the third trimester, the IT phase was dominant (48.7%), followed by the HBeAg-positive IP phase (24.6%), the HBeAg-positive IA phase (9.4%), the inactive carrier (IC) phase (9.4%), the HBeAg-negative IP phase (7.1%), and the HBeAg-negative IA phase (0.9%). During the postpartum period, a numerically higher cumulative incidence of phase maintenance (p = 0.150) and a significantly lower cumulative incidence of transition to the HBeAg-positive IA phase (p < 0.001) were observed in pregnant women in the IT phase compared with those in the HBeAg-negative IP phase. The cumulative incidence of phase maintenance (p = 0.900) and transition to the HBeAg-negative IA phase (p = 0.560) were comparable between pregnant women in the IC phase and those in the HBeAg-negative IP phase. The risk of postpartum liver disease progression was low among pregnant women across all disease phases.

Pregnancy may have a pronounced impact on the dynamics of HBV infection in HBeAg-positive patients, particularly those in the IP phase at 24–28 weeks of gestation. Close postpartum monitoring is therefore warranted for this specific population.