Incidence and predictors of elevated postpartum alanine aminotransferase in chronic hepatitis B mothers: a prospective study protocol.

Background: The majority of HBeAg-positive mothers with chronic hepatitis B have high levels of viremia and inactive disease with normal alanine aminotransferase (ALT) during pregnancy. In addition, postpartum disease activation and ALT flare have been reported in the range of 15 - 35%. However, the current International Association Guidelines have not provided clear recommendations and a risk-stratified monitoring schedule. Furthermore, data are lacking on the definition of normal ALT in the postpartum period in mothers with chronic hepatitis B. The clinical features and ALT flare patterns in HBeAg-positive mothers versus HBeAg-negative mothers are not fully explored. Thus, we design a cohort study to investigate the aforementioned area and generate data to assist healthcare providers in better managing mothers with hepatitis B. We aim to assess the frequency of postpartum ALT flares and predictors for such events.

Method: This study is a single-center and prospective cohort study (n = 360) that consists of two groups of patients including HBsAg-positive mothers (n = 120) and healthy mothers without HBV infection (n = 240). In HBeAg-positive mothers, antiviral therapy during late pregnancy is permitted to prevent Mother-to-child transmission (MTCT) but discontinued at delivery if there is no further indication for the treatment. Mothers are enrolled at the gestational weeks of 12-24. After delivery, both mothers and their infants will be followed up until postpartum week 24. Clinical and laboratory data are collected every 4 weeks during the study except there are no follow-up visits at the postpartum weeks 16 and 20. The primary objective is the proportion of patients with postpartum ALT flares. The secondary objectives are independent risk factors during pregnancy for predicting postpartum ALT flares and the normal range of postpartum ALT levels in healthy mothers.

Discussion: The current study focuses on the incidence of postpartum ALT flares in mothers with chronic hepatitis B including subgroup analysis based on HBeAg status. The data will have several clinical implications, such as providing evidence for an appropriate monitoring schedule in CHB mothers after delivery. Further analyses on predictors of such events may assist clinicians in identifying mothers who might develop severe postpartum ALT flares. The data generated from healthy mothers have the potential to identify the patterns of ALT changes during pregnancy and postpartum, so we can gain a better understanding of the normal range of ALT in this subpopulation.

Trial Registration Number At The Chinese Clinical Trial Registry: ChiCTR2200061130.