Labor Induction & Augmentation

Oxytocin can save a stalled labor or rupture a uterus — the difference is how you titrate it, when you stop it, and what you're watching on the monitor.

Induction initiates labor that hasn't started; augmentation strengthens contractions already present. Both use the same tools but for different clinical pictures. Cervical ripening comes first when the Bishop score is less than 6 — misoprostol (Cytotec) or dinoprostone (Cervidil) soften the cervix before oxytocin begins. Critical rule: prostaglandins (both misoprostol and dinoprostone) are contraindicated with a prior uterine scar due to uterine rupture risk; misoprostol carries the greatest danger. Oxytocin (Pitocin) is titrated in milliunits per minute, typically starting at 1-2 mU/min and increasing by 1-2 mU/min every 15-30 minutes per protocol. The goal is contractions every 2-3 minutes, lasting 60-90 seconds, with adequate resting tone between them. Tachysystole — more than 5 contractions in 10 minutes averaged over 30 minutes — requires immediate action: stop the oxytocin, reposition the patient to left lateral, administer IV fluid bolus, and give oxygen if the fetal heart rate is nonreassuring. Terbutaline 0.25 mg subcutaneous may be ordered as a tocolytic rescue. Oxytocin has an antidiuretic effect, so monitor for water intoxication — watch for decreased urine output, headache, and hyponatremia. Amniotomy (artificial rupture of membranes) may accompany either induction or augmentation; after AROM, document fluid color, odor, amount, and fetal heart rate immediately.

Key Distinctions

Don't confuse induction (starting labor) with augmentation (boosting existing labor) — the Bishop score threshold matters only for induction decisions. Students mix up misoprostol and dinoprostone: for NCLEX purposes, both prostaglandins are contraindicated with a prior uterine scar, though misoprostol carries the highest rupture risk. Tachysystole is defined by contraction frequency (>5 in 10 min), not by contraction strength alone.

Clinical Pearl

Pit goes up slow, comes off fast. If you see tachysystole, stop the drip first, ask questions second — the uterus needs to relax so the fetus can recover.