Impact of maternal hepatitis B carrier status on congenital abnormalities: a systematic review and meta-analysis

OBJECTIVES: This study aims to explore whether maternal hepatitis B carrier status is associated with an increased risk of congenital abnormalities. DESIGN: A systematic review and meta-analysis of observational studies. DATA SOURCES: PubMed, Embase (Ovid), Scopus, the China National Knowledge Infrastructure (CNKI) and the Wanfang databases. STUDY SELECTION: Five databases were searched systematically from inception to 7 September 2021. Cohort and case–control studies that investigated the association between maternal hepatitis B virus (HBV) infection and congenital abnormalities were included. This study was conducted according to MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently collected data, as well as assessed risk of bias by using Newcastle–Ottawa Scale. We pooled crude relative risk (cRR) and adjusted OR (aOR) by DerSimonian-Laird random-effects model. Heterogeneity was explored by I(2) statistics, Cochran’s Q test. Several subgroup analyses and sensitivity analyses were performed. RESULTS: In total, 14 studies involving 16 205 pregnant women exposed to HBV were included. The pooled cRR of 1.15 (95% CI: 0.92 to 1.45; 14 studies included) showed a marginal but not significant association between maternal HBV-carrier status and congenital abnormalities. However, the pooled aOR of 1.40 (95% CI: 1.01 to 1.93; 8 studies included) indicated that pregnant women with HBV infection might be associated with a higher risk of congenital abnormalities. Subgroup analyses of adjusted data showed a higher pooling cRR or aOR on high prevalence HBV infection populations, as well as studies from Asia and Oceania. CONCLUSIONS: Maternal hepatitis B carrier status might be at potential risk for congenital abnormalities. The existing evidence was not sufficient to draw a firm conclusion. Additional studies may be warranted to confirm the association. PROSPERO REGISTRATION NUMBER: CRD42020205459.