3.4 Labor Induction & Augmentation
Key Takeaways
- The Bishop score describes dilation, effacement, station, consistency, and position. A higher score predicts greater induction success; an unfavorable score often prompts consideration of cervical ripening rather than an automatic rule.
- Misoprostol should not be used for cervical ripening or induction at term after a prior cesarean or major uterine surgery; mechanical methods may be options when otherwise appropriate.
- Oxytocin is a high-alert medication requiring a standardized concentration, independent checks, pump administration through the proximal port, continuous maternal-fetal assessment, and titration under the facility protocol.
- For tachysystole with an adverse FHR pattern, stop oxytocin, reposition, assess urgent causes and maternal hemodynamics, treat hypotension, and consider ordered tocolysis; give oxygen for maternal hypoxemia.
3.4 Labor Induction & Augmentation
Induction initiates labor before spontaneous onset; augmentation strengthens labor that has begun but is inadequate. Safe nursing care combines a valid indication, informed consent, cervical assessment, continuous response evaluation, and disciplined use of high-alert medications.
Indications, Contraindications & Postterm Pregnancy
Common indications include membrane rupture, hypertensive disease, diabetes or other maternal disease, fetal-growth concerns, oligohydramnios, infection requiring birth, and late-term or postterm pregnancy. Gestational age must be verified because risk rises as pregnancy continues. Surveillance or planned induction near and beyond 41 weeks follows the obstetric plan; a patient-specific discussion should address dating certainty, fetal status, cervical findings, benefits, alternatives, and preferences.
Do not induce vaginal birth when vaginal delivery itself is contraindicated, such as placenta or vasa previa, transverse lie, cord prolapse, or a prior classical uterine incision. A failed induction is not diagnosed merely because latent labor is slow; allow adequate ripening and oxytocin time when maternal and fetal status permit.
Bishop Score & Cervical Ripening
The Bishop score uses five findings: dilation, effacement, station, cervical consistency, and cervical position. A score of 8 or more is generally favorable; a score of 6 or less is often considered unfavorable. The score predicts probability—it does not by itself require or prohibit a method.
- Mechanical methods: A transcervical balloon applies local pressure and has relatively low tachysystole risk. It may be considered after a prior low-transverse cesarean when the overall plan supports TOLAC.
- Misoprostol (PGE1): Follow the low-dose institutional regimen and delay oxytocin for the specified interval after the last dose. Do not use it for term ripening or induction after prior cesarean or major uterine surgery.
- Dinoprostone (PGE2): A removable vaginal insert permits prompt removal for tachysystole or an adverse FHR response. Follow the product and facility interval before oxytocin.
- Amniotomy: Confirm presentation, engagement or safe station, and FHR before and immediately after membrane rupture because cord prolapse and abrupt FHR change are key hazards.
Consent, Readiness & Ongoing Reassessment
Before starting, verify the reason for induction, dating, presentation, placental location, membrane status, baseline FHR, maternal vital signs, relevant laboratory results, and ability to respond to an emergency. Explain the proposed method, expected sequence, pain options, alternatives, the possibility of a prolonged latent phase, and circumstances that would change or stop the plan. Respect refusal or a request to pause for clarification.
Induction success is not judged by a single clock. Document cervical change and maternal-fetal response, allow adequate time for ripening and oxytocin when status is reassuring, and reassess whether the original indication, method, and staffing remain appropriate. Suspected infection, hemorrhage, uterine rupture, cord prolapse, or persistent Category III FHR changes require a different pathway rather than simply increasing stimulation.
Oxytocin: High-Alert Administration
Use the standardized concentration and order set. Independently verify the patient, indication, solution, concentration, pump settings, line tracing, and emergency stop plan. Connect the secondary infusion at the port closest to venous access so stopping the pump limits residual drug delivery. Continuously assess FHR, contraction frequency and duration, resting tone, maternal vital signs, fluid balance, pain, and labor progress.
Start and titrate only at protocol-defined increments and intervals. The goal is adequate labor progress with uterine relaxation between contractions and a reassuring fetal response—often about three to five contractions in 10 minutes, not one mandatory number. More oxytocin is not better once an adequate pattern is present. Prolonged high-dose infusion and excess electrolyte-free fluid can contribute to water intoxication; watch intake, output, sodium-related symptoms, and pump accuracy.
Tachysystole & Adverse FHR Response
Tachysystole is more than five contractions in 10 minutes averaged over 30 minutes. Prolonged contractions and elevated resting tone are separate abnormalities. Management is driven by the FHR response, cause, and maternal condition:
- Assess the tracing and patient at bedside; call for help for Category III, prolonged bradycardia, bleeding, severe pain, hypotension, or concern for rupture, abruption, or cord prolapse.
- Stop oxytocin for tachysystole with an adverse FHR pattern; for a reassuring pattern, reduce or stop it according to protocol while reassessing.
- Reposition laterally, correct maternal hypotension, and use IV fluid judiciously. Give supplemental oxygen for maternal hypoxemia, not routinely when saturation is normal.
- If excessive uterine activity and the adverse tracing persist, prepare an ordered rapid-acting tocolytic and expedited birth as the situation requires.
- Resume oxytocin only after uterine activity and FHR have recovered, using the dose and timing specified by the order set rather than a universal percentage or clock rule.
Document the tracing, uterine activity, pump changes, bedside assessment, notifications, interventions, response, and shared plan in real time.
A multiparous patient at 41 weeks gestation undergoes cervical assessment prior to labor induction. Her examination shows: dilation 3 cm (2 pts), effacement 70% (2 pts), station -1 (2 pts), soft consistency (2 pts), and anterior position (2 pts), yielding a total Bishop score of 10. How should the nurse interpret this finding?
A laboring patient receiving an oxytocin infusion exhibits 7 uterine contractions in a 10-minute period over a 30-minute observation window. The fetal heart rate tracing demonstrates a Category I pattern with baseline 140 bpm and moderate variability. How should the nurse define and manage this uterine pattern?
An oxytocin infusion is being administered to augment labor in a primigravida. The electronic fetal monitor displays uterine tachysystole accompanied by recurrent late decelerations and loss of variability (Category III FHR). What is the nurse's immediate priority intervention?