The hepatitis B virus infection characterized by positive HBsAg during pregnancy is an unneglectable issue in developing countries, but the association between HBsAg positivity and adverse maternal outcomes retains uncertain. The paper is aimed to examine the effects of HBsAg positivity during pregnancy on adverse maternal outcomes in the Chinese population. METHODS:

A retrospective cohort study was conducted in Sichuan province, China. A total of 22,374 deliveries were collected from six hospitals between January 1, 2009 and December 31, 2010. The pre-eclampsia, gestational diabetes mellitus (GDM), postpartum hemorrhage (PPH), intrahepatic cholestasis, cesarean section, and placenta previa were pre-specified adverse maternal outcomes. We used two multivariate logistic regression models to assess the association between HBsAg positivity and adverse maternal outcomes: the first adjusted for maternal demographic characteristics, gestational characteristics, and medical interventions; and in the second model, we added gestational co-morbidities to the variables specified in the first model. This study was approved by Medical Ethics Committee of West China Second Hospital, Sichuan University (Approval number: 2014-020 and date of approval: September 18^th