China currently has about 86 million people with chronic hepatitis B virus infection, and infections caused by mother-to-child transmission account for 40% to 50% of new hepatitis B infections. Domestic and international guidelines both recommend that for pregnant women with high viral loads at 24-28 weeks of gestation, oral antiviral therapy should be administered based on a balance of risks and benefits and informed consent, continuing until after delivery, which can significantly reduce the rate of HBV mother-to-child transmission. Studies have reported that antiviral drugs such as tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) can reduce mother-to-child transmission rates in pregnant women with hepatitis B.

It has been reported that among pregnant women with hepatitis B infection and high viral loads but no obvious hepatitis, the incidence of postpartum hepatitis ranges from 15% to 35%. Among pregnant women who received antiviral therapy during pregnancy, 36.3% developed postpartum hepatitis. In a multicenter prospective randomized controlled trial (RCT), Pan and colleagues observed that the proportion of mothers with elevated ALT levels postpartum was 45% for those treated with tenofovir disoproxil fumarate (TDF) during pregnancy versus 30% for those untreated. A large retrospective cohort study involving 4,236 hepatitis B mothers in China found that the rate of postpartum ALT elevation in chronic hepatitis B pregnant women who did not receive antiviral therapy during pregnancy was 28.27%. This study also identified independent risk factors for postpartum ALT elevation, including high viral load during pregnancy. The peak periods of ALT elevation occurred between 4-6 weeks and 9-12 weeks postpartum, showing a bimodal distribution.

To explore the differences in prognosis between groups that did and did not receive antiviral therapy, we will conduct a prospective cohort study to assess the incidence of postpartum ALT elevation in mothers with chronic hepatitis B and identify independent risk factors that can predict postpartum ALT elevation. Our data will help healthcare providers better manage pregnant women with chronic hepatitis B.

Inclusion Criteria:

Female; Between 20-40 years old; HBsAg positive for more than 6 months; ALT ≤40 U/L; Any time point from 24 weeks of pregnancy to delivery; For HBV viral load >2x10^5 IU/ml, regular TDF medication is required and should be stopped immediately after delivery; For HBV viral load <2x10^5 IU/ml, antiviral treatment is not needed; All patients should have good adherence.

Exclusion Criteria:

Accompanied by hepatitis A, C, E viruses or other hepatotropic viral infections or AIDS; accompanied by cirrhosis, liver cancer, or other chronic liver diseases; accompanied by diseases of vital organs such as heart, lungs, or kidneys; accompanied by autoimmune hepatitis, autoimmune diseases, hypertension, diabetes, thyroid diseases; previous pregnancy with complications; previous pregnancy with fetal or neonatal growth and developmental defects; previous or current use of nephrotoxic drugs, glucocorticoids, cytotoxic drugs, or immunomodulators; ultrasound before medication indicates fetal malformations, abnormal fetal development, placental abnormalities, or threatened miscarriage; use of anti-hepatitis B virus drugs within six months before pregnancy; failure to follow up regularly according to the study plan.

Postpartum condition of pregnant women with chronic hepatitis B