Aim: This study aimed to describe the prolonged passive second stage of labour in nulliparous women in relation to its prevalence, risk factors, birth outcomes, midwives’ intrapartum management, and women's birth experiences. Methods: Study I was a qualitative study in which 36 midwives participated in seven focus group discussions. Data were analysed using qualitative content analysis. Studies II and III were retrospective observational cohort studies where medical records from 1131 nulliparous women in Sweden were reviewed. Analyses were performed using descriptive statistics and multivariable logistic regression. Study IV included 15 individual interviews with nulliparous women who had a passive second stage lasting three hours or more. Data were analysed using thematic analysis based on descriptive phenomenology. Results: Midwives’ management of the passive phase is complex, especially if progress is slow. Guidelines were considered, but women were preferably managed individually. The prevalence of prolonged passive second stage (≥2h) was 38%. Epidural analgesia, malpresentation, maternal age ≥30 years, and birth weight of ≥4 kg were identified as risk factors for prolonged passive second stage. Longer duration of the passive second stage was associated with an increased risk of operative delivery. There were no associations with adverse maternal outcomes. Associations with adverse neonatal outcomes were found, although the rate of adverse neonatal outcomes were low in the study population. Women’s experiences of prolonged passive second stage were described in four themes: “An unknown phase”, “Trust and mistrust in the body’s ability”, ”Loss of control“, and “Support through presence and involvement”. Conclusion: This thesis describes the prolonged passive second stage from multiple perspectives, including midwives, epidemiological data, and women’s experiences. The midwives’ management of the passive second stage included a complex continuous process of assessment and balancing options for the next step. A prolonged passive second stage was common and did not result in increased risks of adverse maternal outcomes, although further fetal surveillance can be called for. Nulliparous women experienced the passive second stage as an unknown phase and expected a different path for birth, and the experience could include loss of control and increased need for emotional and physical support.