Duration of labour with spontaneous onset

Area of Science:

• Obstetrics and Gynecology
• Reproductive Health
• Clinical Medicine

Background:

• Labor duration varies significantly among women.
• Parity, the number of previous births, is a known factor influencing labor progression.
• Understanding labor dynamics is crucial for optimizing maternal and infant outcomes.

Purpose of the Study:

• To analyze the duration of spontaneous labor stages based on maternal parity.
• To quantify the relationship between parity and the length of the latent, active, and second stages of labor.
• To explore correlations between different labor phases and stages in relation to parity.

Main Methods:

• Retrospective analysis of 2242 women with spontaneous onset of labor.
• Categorization of women into parity groups: para 0 (nulliparous), para 1 (uniparous), and para 2+ (multiparous).
• Measurement of median and percentile durations for the first (latent and active phases) and second stages of labor.

Main Results:

• Median labor duration decreased with parity: 8.25 hours (para 0), 5.5 hours (para 1), and 4.75 hours (para 2+).
• The latent phase of the first stage of labor was approximately 2.5 times longer than the active phase.
• For para 1+ mothers, labor stages were 60-70% shorter than for para 0 mothers, with weak correlations between individual phase lengths.

Conclusions:

• Maternal parity is a significant determinant of spontaneous labor duration.
• Subsequent births lead to progressively shorter labor durations, particularly in the first and second stages.
• While parity strongly influences labor length, individual phase durations show weak predictive correlations, suggesting multifactorial influences on labor progression.