BACKGROUND:
The passive phase of the second stage of labor is increasingly recognized as a normal component of labor. However, it remains poorly characterized, especially in healthy labouring women.

OBJECTIVES:
To estimate the prevalence of the passive phase of the second stage of labor in healthy women, and to identify associated antenatal and intrapartum factors, as well as maternal and neonatal outcomes.

METHODS:
A retrospective cross-sectional study was conducted using data from women who gave birth in an Italian hospital between 2019 and 2023. Healthy labouring women were included while where excluded women who received epidural analgesia or underwent intrapartum interventions. Data were extracted from electronic records and analyzed overall and by parity.

RESULTS:
Among 2,810 eligible women, 466 (16.6%) experienced a passive phase of the second stage, with a median duration of 30 minutes. This phase was significantly more frequent in nulliparous women (63.9%; p < 0.001). Its occurrence was associated with more advanced cervical dilatation at partograph initiation (p < 0.001) and longer second-stage durations (p < 0.001), even when stratified by parity. In nulliparous women, the passive phase was significantly associated with a higher likelihood of episiotomy (p = 0.02) and lithotomy position during birth (p = 0.013). Among multiparous women, it was linked to higher rates of macrosomia (p = 0.001) and neonatal admission to NICU (p = 0.009). No significant association with mode of birth was found in either group.

CONCLUSIONS:
The passive phase occurred in a minority of healthy laboring women and may be underdiagnosed due to reliance solely on vaginal examinations and inconsistent definitions.

KEY MESSAGE:
Its recognition, particularly following an advanced cervical dilation at partograph initiation, may support a normal approach of labor progression and reduce unnecessary interventions. Labour and birth - evidence