ObjectiveTo investigate the effect of pregnancy complicated with the hepatitis B infection on the pregnancy outcome, immunological factors and the subgroup of lymphocytes in neonates.MethodsSubjects admitting to this hospital between January 1, 2016 and January 1, 2018 in this study were divided into two groups according to the hepatitis B infection, i.e. the observation group (infection) and the control group (healthy), with 60 subjects in each group. Pregnancy complications and the neonatal complications were all recorded, and furthermore, the subgroups of lymphocytes and the levels of immunoglobin in the umbilical cord blood were measured.ResultsThe incidence rates of the premature rupture of fetal membranes, premature delivery, postpartum hemorrhage and pregnancy-induced hypertension syndrome in the observation group were all higher than those in the control group, and the differences had statistical significance. In the observation group, the incidence rates of the neonatal distress and asphyxia, and the levels of neonatal CD3+, CD4+, CD19+, IgA and IgM varied significantly from those in the control group, and the differences showed statistical significance. However, no significant differences were identified in comparison of the incidence rate of the cesarean delivery, neonatal deformity, neonatal death, or levels of neonatal CD8+ and IgG.ConclusionDuring pregnancy, complications of hepatitis B infection results in the increases in the incidence rates of the premature rupture of fetal membranes and neonatal asphyxia, with influences on the levels of immunological factors and lymphocyte subgroups in the umbilical cord blood.