Overview

• Oxytocin is a naturally occurring hormone used pharmacologically to induce or augment labour by stimulating uterine contractions.

• It is a high-risk drug: incorrect use can lead to maternal and fetal complications, including uterine hyperstimulation, fetal hypoxia, and uterine rupture.

2. Indications

1. Labour induction: for post-dates, pre-labour rupture of membranes, maternal medical indications (e.g., hypertension, diabetes).

2. Labour augmentation: when labour is slow due to inadequate uterine contractions.

3. Avoid routine use in normally progressing labour — should not be used simply to accelerate labour or fit schedules.

3. Principles of Safe Use

• Start low, go slow: begin with a low-dose infusion; increase gradually.

• Target contraction frequency: aim for 3–4 effective contractions per 10 minutes.

• Continuous monitoring: maternal vital signs and continuous fetal heart rate monitoring (CTG) are mandatory.

• Assess labour progress: vaginal examination every 1–2 hours after starting augmentation.

• Stop/reduce infusion if:

  • Contractions are too frequent (>5–6 per 10 min)

  • Uterus shows poor relaxation between contractions

  • Fetal heart rate becomes abnormal

4. High-Risk Situations

• Previous cesarean or uterine surgery: increased risk of uterine rupture; use half-dose regimen, with close monitoring.

• Multiple pregnancy or malpresentation: caution; oxytocin may worsen complications.

• Severe preeclampsia or eclampsia: avoid rapid augmentation due to maternal cardiovascular strain.

5. Potential Complications of Misuse (“Abuse”)

• Uterine tachysystole / hyperstimulation → fetal hypoxia, acidosis, neonatal complications.

• Uterine rupture, especially in scarred uterus.

• Postpartum hemorrhage, due to uterine fatigue or trauma.

• Increased instrumental delivery rates.

• Fetal distress, low Apgar scores, seizures, perinatal asphyxia.

6. Monitoring and Safety

• Fetal monitoring: continuous CTG throughout oxytocin infusion.

• Maternal monitoring: pulse, blood pressure, uterine tone.

• Documentation: indication, infusion rate, monitoring, maternal/fetal response, and any dose adjustments.

• Escalation: senior review if poor progress, hyperstimulation, or fetal compromise.

7. Key Exam Points

• Oxytocin is beneficial when indicated but potentially harmful if used indiscriminately.

• Misuse is common in over-medicalized labour or poorly monitored settings.

• Correct titration and continuous monitoring reduce risks.

• Always assess underlying cause of slow labour before starting oxytocin.

• In women with prior cesarean, always use reduced-dose regimen.

• Immediate action is required for hyperstimulation: stop infusion, reposition mother, give oxygen, consider tocolysis, senior review.

8. Summary Table: Safe Oxytocin Use