The study compared two ways of monitoring labor in pregnant women with high blood pressure. Using Zhang's newer guideline cut down C‑sections and some interventions but led to more postpartum bleeding and forceps deliveries. It also showed that older moms and those using fertility tech were more common in the newer group, but baby outcomes were similar.

Zhang's guideline and the 1994 WHO partograph are both used to monitor labor progress. Zhang's guideline defines labor's active phase as cervical dilation of 6 cm (vs. 4 cm in the 1994 WHO partograph) and emphasizes individualized care with extended labor observation. Conversely, the 1994 WHO partograph uses a standardized "action line" for earlier intervention. This study compared Zhang's guideline and the1994 WHO partograph in managing hypertensive disorder of pregnancy (HDP), specifically evaluating labor interventions, maternal age disparities, and postpartum outcomes. This retrospective cohort study analyzed clinical data from 5806 nulliparous women with singleton full-term pregnancies who were diagnosed with HDP between 2010 and 2023. Participants were stratified into the 1994 WHO partograph (January 2010-August 2014, N = 2100) and Zhang's guideline cohorts (September 2014-December 2023, N = 3706). The primary endpoints were the intrapartum cesarean and postpartum hemorrhage (PPH) rates. Secondary endpoints included the rates of labor intervention (oxytocin augmentation, artificial membrane rupture, and lateral episiotomy), forceps-assisted delivery, and neonatal asphyxia (5-min Apgar score < 7). Zhang's guideline significantly reduced the intrapartum cesarean (10.96% vs.13.33%, P < 0.0001) and labor intervention rates (16.06% vs.43.62%, P < 0.0001) but increased the rates of PPH (20.02% vs.11.24%, P < 0.0001) and forceps-assisted delivery (19.67% vs.7.90%, P < 0.0001). Zhang's guideline group included a higher of advanced maternal age (AMA, ≥ 35 years) pregnancies (20.72% vs.9.24%, P < 0.0001) and assisted reproductive technology (ART) usage (6.99% vs.0.90%, P < 0.0001). The frequency of neonatal asphyxia did not differ between the groups. Multivariate analysis illustrated that the use of Zhang's guideline (odds ratio [OR] = 2.101, P < 0.0001), prolonged labor (OR = 1.607, P = 0.0052), and intrapartum cesarean section (OR = 6.024, P < 0.0001) were independent risk factors for PPH. Compared with the 1994 WHO partograph, Zhang's guideline for managing HDP effectively reduced intrapartum cesarean sections and labor interventions. Zhang's guideline also proved more adaptable to pregnancies involving AMA and ART without increasing the risk of neonatal asphyxia. However, its implementation was associated with higher rates of PPH and forceps delivery. Notably, the protocol itself emerged as an independent risk factor for PPH.