Maternal chronic HBV infection would not increase the risk of pregnancy-induced hypertension--results from pregnancy cohort in Liuyang rural China.

The relationship between maternal HBV (hepatitis B virus) infection and pregnancy-induced hypertension (PIH) is inconclusive. Few studies have been conducted in rural areas of China. In order to examine the association between maternal chronic HBV infection and risk of PIH in Liuyang rural area China, we enrolled 6,195 eligible pregnant women in 2010-2011 in selected 14 towns of Liuyang on their first prenatal visit to local maternity care unit. A total of 461 subjects (7.44% (95%CI: 6.79%, 8.10%)) were identified with positive HBsAg status (exposed group) and 5734 were non-HBV carriers (unexposed group). Multivariate log-binomial regression models were used to estimate the risk of PIH, gestational hypertension (GH), and preeclampsia (PE) in relation to maternal chronic HBV infection. There are total of 455 subjects diagnosed with PIH (7.34% (95%CI: 6.70%, 7.99%)), including 371 GH (5.99% (95%CI: 5.40%, 6.58%)) and 81 PE (1.31% (95%CI: 1.07%, 1.64%)). The crude risk ratio between PIH, GH, PE and maternal HBV infection were 1.20 (95%CI: 0.88, 1.64), 1.30(95%CI: 0.93, 1.81) and 0.79 (95%CI: 0.32, 1.93), respectively. After adjustment for gravidity history, abortion history, family history of Diabetes Mellitus (DM) and family history of hypertension, positive HBsAg status was still not significantly associated with PIH (RR = 1.18, 95%CI: 0.87, 1.62), GH (RR = 1.27, 95%CI: 0.91, 1.78) or PE (RR = 0.79, 95%CI: 0.32, 1.95). Additional adjustment for maternal age, marital status, parity history, family history of DM, Body Mass Index at first antenatal visit, folic acid supplementation, smoking status during pregnancy and economic status of living area, multivariate analysis provided similar results. In conclusion, our study found that maternal chronic HBV infection prevalence rate is 7.4% among Liuyang rural area and there is no significant association between maternal HBV infection and the risk of PIH, GH or PE.