Mode of delivery and birth outcomes in relation to the duration of the passive second stage of labour: A retrospective cohort study of nulliparous women.

Abstract

ObjectiveTo investigate the mode of delivery and birth outcomes in relation to the duration of the passive second stage of labour in nulliparous women.Methods and findingsA retrospective cohort study of all nulliparous women (n = 1131) at two delivery units in Sweden. Maternal and obstetric data were obtained from electronic medical records during 2019. The passive second stage was defined as the complete dilation of the cervix until the start of the active second stage. The duration of the passive second stage was categorized into three groups: 0 to 119 min (0 to ConclusionsOur study demonstrates an increased risk of operative delivery for a longer duration (>2h) of the passive second stage in nulliparous women, although most of the women gave birth by spontaneous vaginal delivery even after ≥4 hours. There was no evidence of an increased risk of adverse maternal outcomes in a longer duration of the passive second stage but there were indications of increased adverse neonatal outcomes. Assessment of fetal well-being is important when the duration of the passive phase is prolonged.