The characteristics and predictors of postpartum hepatitis flares in women with chronic hepatitis B

We aimed to characterize postpartum disease flares among treatment-naive mothers with chronic hepatitis B (CHB). CHB mothers were enrolled and compared with non-infected mothers in terms of postpartum alanine aminotransferase (ALT) abnormalities. Demographic, virological, and biochemical parameters were collected up to postpartum week 16, with flares and exacerbations defined as ALT levels 5–10 and >10 times the upper limit of normal, respectively. Outcome assessments included ALT flares or exacerbation and their predictive parameters. Among 4236 patients enrolled, 869 and 3367 had no infection (group A) and had CHB (group B), respectively. Infected mothers were further stratified into two subgroups by the presence (B1, n = 1928) or absence (B2, n = 1439) of detectable serum levels of hepatitis B virus (HBV) DNA (lowest level of quantitation, 100 IU/mL). A significantly higher frequency of abnormal ALT levels was observed in group B vs. group A (28.27 vs. 20.37%, p < 0.001). ALT events mainly occurred in group B1 (flares, 115/1928, 5.96%; exacerbations, 57/1928, 2.96%). The ALT levels had a bimodal pattern, with peaks at postpartum weeks 3–4 and 9–12. On multivariate analysis, elevated ALT levels and detectable levels of HBV DNA at delivery were independent risk factors for postpartum disease flares. Further subgroup analysis in group B1 demonstrated that a cut-off HBV DNA level of 5 log10 IU/mL at delivery predicted ALT events (positive predictive value, 14.4%; negative predictive value, 98.2%). Postpartum ALT level elevation is common in CHB patients. ALT flares or exacerbations are mainly observed in mothers with elevated ALT or HBV DNA levels ≥5 log10 IU/mL at delivery.