The study looked at how high blood pressure problems during pregnancy change the length of labor stages. Women with these conditions had a quicker first stage but slower later stages, and they needed more oxytocin to help labor. The findings mainly matter for doctors managing childbirth, not for everyday health hacks or performance tips.

Hypertensive disorders in pregnancy (HDP) are a major cause of maternal and perinatal morbidity and mortality. The impact of HDP on labor stage duration and maternal and neonatal outcomes in nulliparous women remains unclear. To assess labor stage duration and maternal and neonatal outcomes in nulliparous women with HDP. A retrospective cohort of 31 472 singleton pregnancies from January 2018 to December 2023 at the Obstetrics and Gynecology Hospital of Fudan University was analyzed using 1:4 propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). Labor stage durations and maternal and neonatal outcomes were analyzed between women with and without HDP. HDP pregnancies had shorter first and total labor stages but longer second and third stages. The HDP group also had higher oxytocin (OCT) use, reduced fetal distress, intrapartum fever, and increased postpartum hemorrhage. Subgroup analysis by labor onset showed that for spontaneous onset, the HDP group had a significantly shorter first stage and total labor duration, with a significantly longer second and third stage duration. In subgroup analysis by HDP type, among pregnancies with spontaneous onset, those with superimposed preeclampsia on chronic hypertension had the shortest labor duration, followed by gestational hypertension and preeclampsia groups, with chronic hypertension alone showing the longest. Similarly, in the induced labor subgroup, gestational hypertension had the shortest duration, followed by superimposed preeclampsia and preeclampsia, with chronic hypertension again exhibiting the longest. The study indicates HDP affects labor duration, with implications for obstetric policies and childbirth safety.