Risks Associated with Prolonged Latent Phase of Labor

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Perinatal Research

Background:

• The latent phase of labor is a critical period in childbirth.
• Understanding factors influencing labor progression and outcomes is essential for optimizing maternal and neonatal care.
• Prolonged labor phases can be associated with adverse outcomes, necessitating further investigation.

Purpose of the Study:

• To evaluate the association between a prolonged latent phase (PLP) and maternal and neonatal morbidity.
• To compare outcomes in patients with and without PLP, stratified by labor induction status and mode of delivery.

Main Methods:

• Secondary analysis of a prospective cohort study (2010-2015) including 6,509 term gravidas.
• PLP defined as labor duration ≥90th percentile from admission to active labor (6 cm).
• Composite maternal and neonatal morbidity outcomes assessed using multivariable logistic regression, adjusted for confounders.

Main Results:

• Patients with PLP showed significantly increased composite maternal morbidity in both induced (aOR: 1.36) and spontaneous labor (aOR: 1.49).
• Neonatal morbidity was significantly increased in spontaneous labor with PLP (aOR: 1.57).
• Cesarean delivery rates were higher in the PLP group (25.1% vs. 14.0%), but PLP's association with maternal morbidity persisted even after adjusting for delivery mode.

Conclusions:

• A prolonged latent phase at or above the 90th percentile is linked to increased maternal morbidity, irrespective of labor induction or cesarean delivery.
• In spontaneous labor, PLP is also associated with a higher risk of neonatal morbidity.
• Further research is warranted to define optimal latent phase cut-offs for clinical management guidelines.