A systematic review indicates that HBV infection can lead to an increase in pro-inflammatory cytokines in pregnant women, thereby affecting insulin regulation and promoting the secretion of oxytocin by uterine smooth muscle cells, which in turn increases the risk of gestational diabetes mellitus (GDM) and preterm birth; HBV infection can also enhance the compensatory synthesis of bile acids through the HBV viral envelope protein Pre-S1.4 The gene discussed is OXT; the disease is gestational diabetes.