Obstetrics Chapter 27: Prolonged Labor

Prolonged Labor

• Defined as the combined duration of the first and second stages exceeding 18 hours.
• Characterized by protracted cervical dilatation and/or inadequate descent of the presenting part.
• Prolonged labor is identified when the cervical dilatation rate is less than 1 cm/h for a minimum of 4 hours.
• Not synonymous with inefficient uterine contractions; these can be a contributing factor.

Prolonged Latent Phase

• The preparatory phase before actual labor onset; averages 8 hours for primigravidae and 4 hours for multiparae.
• Considered abnormal if exceeding 20 hours in primigravidae and 14 hours in multiparae.
• Causes include unripe cervix, malpresentation, cephalopelvic disproportion, premature rupture of membranes, induction of labor, and early regional anesthesia onset.
• Generally managed with expectant care unless there are indications for expediting delivery.
• Rest and analgesics recommended; augmentation typically involves medical methods, avoiding amniotomy.
• Prolonged latent phase is not an indication for cesarean delivery.

Causes of Prolonged Labor

• Factors affecting the first stage include:

  • Fault in power: uterine inertia or incoordinate contractions.
  • Fault in passage: contracted pelvis, cervical dystocia, pelvic tumors, or full bladder.
  • Fault in passenger: malposition (occipito posterior) and malpresentation (face, brow), congenital fetal anomalies.

• In the second stage, sluggish descent can result from:

  • Fault in power: uterine inertia, inability to bear down, regional anesthetics affecting contractions, or constriction ring.
  • Fault in passage: cephalopelvic disproportion, contracted pelvis, spasm or scarring of pelvic floor/perineum, or soft tissue tumors.

• Poor administration of sedatives and analgesics before active labor can also lead to non-dilatation of the cervix.