Comparison of Labetalol With Versus Without Magnesium Sulfate on Intraoperative Blood Pressure Variability During Cesarean Delivery in Hypertensive Disorders of Pregnancy: A Retrospective Cohort Study.

AIM: This study aims to investigate the effects of two medication regimens-labetalol combined with magnesium sulfate versus labetalol alone-on intraoperative blood pressure variability (BPV) and maternal-neonatal outcomes in patients with hypertensive disorders of pregnancy (HDP) undergoing cesarean delivery.

METHODS

This retrospective cohort study enrolled 170 HDP patients who underwent cesarean delivery at TongXiang Maternity and Child Health Care Hospital between January 2023 and June 2025. Based on perioperative medication regimens, patients were divided into a combination group (labetalol plus magnesium sulfate, n = 86) and a monotherapy group (labetalol alone, n = 84). After propensity score matching (PSM), a cohort of 54 patients was included in each group for analysis. All patients received oral labetalol for preoperative blood pressure control and postoperative management. Patients in the combination group additionally received intravenous magnesium sulfate. The primary outcome measure was the standard deviation of intraoperative systolic blood pressure (SD of systolic blood pressure (SBP)). Secondary outcomes included intraoperative blood pressure target attainment rate, incidence of severe hypertensive events, and maternal-neonatal complications.

RESULTS

After PSM, baseline characteristics were balanced between the two groups. The combination group exhibited a significantly lower intraoperative SD of SBP compared to the monotherapy group (p < 0.001), along with a higher intraoperative blood pressure target attainment rate (p < 0.001) and a lower incidence of severe hypertensive events (p = 0.030). Regarding maternal-neonatal outcomes, the combination group had significantly higher 1‑minute and 5‑minute Apgar scores (p = 0.035 and p = 0.036, respectively) and a lower rate of admission to the neonatal intensive care unit (NICU) (p = 0.002). There were no significant differences between the groups in the incidence of adverse drug events such as hypotension or bradycardia.

CONCLUSIONS

For HDP patients undergoing cesarean delivery, the perioperative application of a combined regimen of labetalol and magnesium sulfate, compared with labetalol alone, was associated with more stable intraoperative blood pressure, reduced variability under surgical stress, and improved early neonatal outcomes. This combined regimen provides valuable clinical reference for optimizing perioperative blood pressure management during cesarean delivery.