Induction of Labour (IOL)

Last updated 08.03.13

 

Definition

-  Attempted artificial initiation of labour of a pregnant women

 

Features

-  Avoided if possible (unless benefit > risks) especially in primips & obese patients

-  Most women enter spontaneous labour prior to 42/40

-  20-30% all labours are induced

-  Women with intact membranes at IOL average 3hrs oxytocin prior to SROM & 16.5hrs to delivery

-  Women with ruptured membranes at IOL average 15.5hrs to delivery

-  May require increased analgesia in labour

-  Increased incidence of Epidural

-  Should be discouraged in primps due to increased LUSCS rate

-  Typically more painful than spontanous labour

- Physiological third stage is contraindicated (due to use of oxytocin and increased risk of PPH)

 

Indications

-  Post dates > 41/40 (42/40)

-  Maternal illness

-  Pre-eclampsia, PIH

-  DM type 1

-  Antiphospholipid syndrome

-  Ruptured membranes

-  Fetal compromise

-  Significant IUGR

-  Abnormal CTG

-  Fetal death

-  Chorioamnionitis

-  Placental abruption

-  Macrosomia

-  Social (controversial)

 

Contrandications

-  Contraindications to vaginal delivery: placenta praevia, etc.

- Caution with high & floating fetal head

 

Complications

-  Failed induction: possible LUSCS vs repeat attempt

-  Increased operative vaginal delivery rate & LUSCS

-  Hyperstimulation (from prostatglandins: Prostin, Cervadil)

-  Abnormal fetal heart patterns (CTG)

-  Uterine rupture

-  Maternal water intoxication

-  Cord prolapse (from ARM)

-  Increased incidence of PPH

 

Methods

-  Prostaglandin applied to posterior fornix

-  Misoprostol Gel (PGE1)

-  Prostin Gel

-  Cervadil Tape

-  Artificial Rupture of Membranes (ARM) & Oxytocin

-  Shortens labour by 1hr+/-

-  Makes contractions stronger

-  Risk of bleeding, infection & cord prolapse

-  Balloon catheters 

-  Mechanical not chemical method

-  More suitable for VBAC

- Not suitable if ruptured membranes or maternal fever

Procedure

- Stretch & sweep may be done prior to attempt to promote spontaneous labour

-  At >40/40 reduces need for IOL for post dates

- Confirm indication & contraindications

- Consent: ensure understand indication, methods & risks

-  CTG 20min+ prior to assessment

- VE for Bishops score

-  Normal CTG + Bishop score >6: Amniotomy (ARM) + Syntocinon

-  Normal CTG + Bishop score <6 (unfavourable cervix): cervical ripening prior to induction

-  Prostaglandins: Prostin, Cervadil

-   Cervadil more appropriate for multips as can remove if hyperstimulation

-   Continous CTG for 60min+ after insertion + vitals

-   Contractions usually commence 1hr post insertion & peak at 4hrs

-   Repeat VE as indicated by method of prostaglandin

-  ARM if favourable +/- Syntocinon

-  May consider Syntocinon prior to ARM to allow head to engage/descend

-  Recommended 12hrs+(?6hrs) between Prostin & Syntocinon

-  OR Cervical ballon

-  If primip & likely unfavourable admit to ward night prior to IOL

-  VE +/- 1st dose prostaglandin (Prostin, Cervadil) 6-10pm night before

-  Prostin usually 2mg 1st dose

- OR insertion of Cervical ballon

-  Repeat VE around 6am for repeat dose of prostaglandin or ARM

-  If multip admit to ward morning of IOL

-  VE +/- 1st dose prostaglandin (Prostin, Cervadil) 6-8am

-  Prostin 1mg 1st dose

-  Avoids delivery during after hours

-  Monitor for failure of induction

 

 

 

References

 

Peninsula Health CPG: IOL PGE2, Prostin; March 2009

Induction of Labour at Term, SOGC CPG, August 2001

RWH CPG: Induction of Labour, May 2011

NICE Guideline CG 70, July 2008