dystocia

Dystocia, or obstructed labor, is an obstetric condition characterized by abnormally slow or difficult labor due to problems with the powers, passage, or passenger. It may manifest as prolonged latent or active labor, failure of cervical dilation to progress, or failure of fetal descent despite contractions. Dystocia increases the risk of maternal and neonatal complications and is a common indication for cesarean delivery in many settings. It requires careful monitoring and timely management.

Causes are typically grouped into three categories: powers (uterine contractions), passage (the birth canal), and passenger (the fetus). Maternal factors include cephalopelvic disproportion (mismatch between fetal size and maternal pelvis), pelvic deformities, malpresentation or malposition (for example, occiput posterior), obesity, and fatigue. Fetal factors include large-for-gestation size (macrosomia), malpresentation or fetal anomalies, and nonreassuring fetal status. Contractions that are infrequent or poorly coordinated also contribute.

Clinical forms of dystocia include prolonged labor, active-phase dilation arrest, and arrest of descent. Active-phase dilation arrest refers to the absence of cervical change for a defined period despite adequate contractions; arrest of descent denotes lack of fetal descent for a period with adequate contractions. Management depends on progress, fetal status, and maternal condition, and may involve augmentation, membrane rupture, or analgesia.

Management focuses on improving labor progression, relieving obstruction, and ensuring fetal well-being. Interventions may include augmentation with oxytocin, amniotomy to release membranes, maternal position changes, analgesia or anesthesia, and treatment of dehydration or infection. If labor fails to progress or fetal distress is present, operative delivery—often cesarean section, or instrumental vaginal delivery when appropriate—may be necessary.

Complications of dystocia include maternal exhaustion, postpartum hemorrhage, uterine atony, infection, or uterine rupture; for the fetus, distress or injury. Risk is higher with obesity, diabetes, advanced maternal age, and prior dystocia. Prevention involves risk assessment, appropriate labor management, and timely intervention when progression stalls.