Gestational hypertension (GH) is a common disorder during pregnancy that can cause adverse pregnancy outcomes. In the present study, magnesium sulfate (MgSO4) combined with labetalol was used for clinical treatment. Randomized controlled trial was conducted in 100 patients with GH, documented in the Department of Obstetrics and Gynecology (Taicang TCM Hospital) grouped into the experimental (Expt) and control (Ctrl) groups (n=50 cases/group). The Ctrl group was treated with MgSO4, whereas the Expt group was treated with MgSO4 + labetalol. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the Expt group were not significantly different from those in the Ctrl group (P>0.05). By contrast, the SBP and DBP were significantly lower after treatment than those before treatment in both groups (P<0.05). Whole blood viscosity, plasma viscosity and hematocrit were significantly lower in the Expt group compared with those in the Ctrl group after treatment (P<0.05). High mobility group box-1 protein, homocysteine and serum cystatin C levels in the Expt group were also markedly lower than those in the Ctrl group after treatment (P<0.05). In the Expt group, the rate of spontaneous vaginal delivery was much higher, whereas the rates of cesarean section and postpartum hemorrhage were markedly lower than those in the Ctrl group (P<0.05). The occurrence of fetal intrauterine distress, placental abruption, neonatal asphyxia, premature birth and neonatal death were also significantly lower in the Expt group than those in the Ctrl group (P<0.05). In conclusion, MgSO4 + labetalol could improve inflammatory stress and the hemodynamics of patients with GH, and may have a marked antihypertensive effect. Thus, it may improve pregnancy outcome and reduce perinatal complications.