From the Guidelines
Management of a prolonged active stage of labor should prioritize thorough evaluation for cephalopelvic disproportion (CPD) and intervention with cesarean delivery (CD) if CPD is suspected or cannot be ruled out, as it is associated with significant risks to both mother and fetus. The approach to managing protracted active labor involves a 2-phased process: evaluation for known associations (assumed cause or contributor to cause) and intervention appropriate to the association found 1.
Initial Assessment
Begin by confirming the diagnosis of protracted active labor, which is characterized by less than 1 cm per hour of cervical dilation in nulliparous women or less than 1.5 cm per hour in multiparous women, despite adequate contractions 1. Assessment of the "3 Ps" - Powers (contraction strength), Passenger (fetal size and position), and Passage (pelvic adequacy) - is crucial.
Intervention
For inadequate contractions, oxytocin augmentation can be considered, starting with a low-dose regimen and increasing as needed until adequate contractions are achieved, with careful monitoring of both the mother and the fetus 1. However, if there is evidence of CPD, such as marked molding, deflexion, or asynclitism of the fetal head without descent, proceeding with CD is a safer option 1. Artificial rupture of membranes may be performed for specific indications but lacks objective proof as a useful treatment for protraction or arrest of dilatation 1.
Monitoring and Decision Making
Continuous fetal monitoring and regular vaginal examinations every 2 hours are essential to assess progress and make informed decisions about the need for intervention 1. If no progress occurs after 4 hours of adequate contractions with oxytocin, or if there are signs of CPD, cesarean delivery should be considered to prevent maternal and fetal complications 1. The frequency of CPD in association with a prolonged deceleration phase is higher, making thorough cephalopelvic assessment imperative before pursuing oxytocin infusion or a difficult vaginal operative delivery 1.
Key Considerations
- Cephalopelvic disproportion (CPD) must be ruled out before attempting vaginal delivery in cases of protracted active labor, as it is a significant risk factor for complications.
- Oxytocin augmentation should be used judiciously, with careful monitoring, and only when CPD has been excluded.
- Continuous fetal monitoring and regular assessments of labor progress are critical for timely intervention.
- Cesarean delivery is the preferred option if CPD is suspected or if labor does not progress despite adequate contractions and oxytocin augmentation, to ensure the safety of both the mother and the fetus 1.
From the FDA Drug Label
Oxytocin Injection, USP (synthetic) is indicated for the initiation or improvement of uterine contractions, where this is desirable and considered suitable, in order to achieve early vaginal delivery for fetal or maternal reasons It is indicated for (1) induction of labor in patients with a medical indication for the initiation of labor, such as Rh problems, maternal diabetes, pre-eclampsia at or near term, when delivery is in the best interest of mother and fetus or when membranes are prematurely ruptured and delivery is indicated; (2) stimulation or reinforcement of labor, as in selected cases of uterine inertia;
The step-by-step management of a prolonged active stage of labor (protracted active phase of labor) may involve:
- Stimulation or reinforcement of labor using oxytocin, as indicated for selected cases of uterine inertia 2
- Monitoring of both the mother and the fetus to determine the best course of action
- Evaluation of the need for augmentation of labor with oxytocin, if uterine contractions are not sufficient to progress labor However, the exact steps may vary depending on the individual case and the clinical judgment of the healthcare provider.