Induction and augmentation of labour: the oxytocin infusion and how to watch for tachysystole

What it is

Induction starts labour; augmentation strengthens contractions in a labour that has started. WHO says both should be done only with a clear indication, in a facility that can perform a caesarean, by staff who can recognise and manage the complications: uterine hyperstimulation, fetal distress and, rarely, uterine rupture. The response to oxytocin varies a lot from one woman to another, so the rate is set and changed only by order and protocol. The nurse's part is the checks before starting, the observations every 30 minutes and stopping the infusion when the uterus contracts too often.

What it requires

• Indications reviewed by WHO include a certain 41 weeks, prelabour rupture of membranes at term, pre-eclampsia, chorioamnionitis, fetal growth restriction and fetal death.
• WHO: do not induce an uncomplicated pregnancy before 41 weeks, or for suspected large baby alone.
• The state of the cervix is scored before induction; with an unfavourable cervix it is ripened first with prostaglandins or a balloon catheter.
• Misoprostol is not used in women with a previous caesarean, who have a higher risk of uterine rupture (WHO).
• Drugs to relax the uterus must be available in case of hyperstimulation (WHO).

Components

• Before: indication, consent, baseline observations and a fetal heart check.
• During: an infusion prepared and labelled according to protocol, with observations every 30 minutes.
• If hyperstimulation: stop, position, reassess, call.
• After the birth: closer watch of the uterus, because induction is a risk factor for postpartum haemorrhage.

How it is applied (and why)

1. Check the written indication and informed consent — induction needs a clear reason and she should know the options.
2. Record pulse, blood pressure, contractions and fetal heart before starting — they are the baseline for every later check.
3. Help her lie on her left side — this protects blood flow to the uterus.
4. Prepare, label and double-check the infusion as the protocol says — the effective amount varies widely between women.
5. Every 30 minutes record rate, contractions in 10 minutes and their length, maternal pulse and fetal heart — hyperstimulation starts fast.
6. Check the arm and the line — a change in arm position can change the flow.
7. If more than 5 contractions in 10 minutes or one over 60 seconds: stop, stay, turn her to the left and listen — then call.
8. If the fetal heart is below 100 or above 180 per minute, stop and manage it as fetal distress — the doctor decides.
9. Watch for a rapid maternal pulse, constant abdominal pain and suprapubic pain — they can signal uterine rupture.
10. After the birth, watch uterine tone and bleeding closely — the risk of haemorrhage is higher after induction.

In nursing practice

• Uterine rupture is more likely in women who have had several births and in women with a scar on the uterus (WHO, CLAP).
• CLAP: excess oxytocin can cause a uterus that does not relax, poor blood flow to the placenta and fetal hypoxia.
• Record the oxytocin on the partograph or Labour Care Guide, which has a row for it.
• Rates, amounts and changes: only by order and institutional protocol.

Common mistakes

• Leaving the woman alone with the infusion running.
• Raising the rate without checking contractions and the fetal heart first.
• Counting contractions without timing how long they last or whether the uterus relaxes between them.
• Restarting the infusion after hyperstimulation without a new order.

Test yourself

Think of the answer, then tap the question to see it.

Add to my cards (4)

Connections

← All of nursing

Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.

Sources: Managing complications in pregnancy and childbirth: a guide for midwives and doctors, 2nd ed. (World Health Organization, 2017); Salud sexual y reproductiva: guías para el continuo de atención de la mujer y el recién nacido focalizadas en APS, 3.ª ed. (CLAP/SMR 1577) (Organización Panamericana de la Salud, CLAP/SMR, 2011); Inducing labor (MedlinePlus, U.S. National Library of Medicine, 2025); WHO Labour Care Guide: user's manual (World Health Organization, 2020).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Send

Representative model, for educational purposes only.