Obstetrics & Gynaecology/Prostaglandin (induction of labour)

Induction agents

also: dinoprostone · misoprostol · PGE2 · oxytocin induction

Overview

Cervical ripening and induction of labour. Prostaglandins ripen the cervix; oxytocin augments established labour.

Mechanism

Prostaglandins (dinoprostone PGE₂, misoprostol PGE₁) soften and efface the cervix and stimulate myometrial contraction. Oxytocin infusion is used after membrane rupture to drive/augment contractions.

Indications

Induction of labour (post-dates, PROM, maternal/fetal indication)
Cervical ripening before induction

The agents

Dinoprostone (Propess/Prostin)PGE₂ vaginal

pessary/gel

Standard UK cervical-ripening agent.

Misoprostol (Mysodelle)PGE₁ vaginal

Also used in miscarriage/PPH; heat-stable.

Oxytocin (Syntocinon)augmentation

IV titrated

After ARM; titrate to contractions.

Adverse effects

Uterine hyperstimulationserious

→ fetal distress; remove pessary / stop oxytocin (± tocolytic).

Uterine ruptureserious

Higher with prostaglandins after previous caesarean.

Nausea, diarrhoea, pyrexiacommon

Cautions & contraindications

Previous classical caesarean / uterine surgeryall

Rupture risk.

Placenta praevia, fetal malpresentation, active genital herpesall

Interactions

Do not give oxytocin within 6 h of vaginal prostaglandin (hyperstimulation)

Monitoring & kinetics

Continuous CTG; uterine activity (Bishop score before induction)

Prostaglandins vaginal; oxytocin IV infusion titrated.

Source: NICE NG207 — Inducing labour · BNF — Prostaglandins