Induction of

Labour SOGC, 2013

WHO, 2011

NICE, 2008

Aboubakr

Elnashar Benha University Hospital,

Egypt

Aboubakr Elnashar

CONTENTS

1. DEFINITIONS

2. SETTING &TIMING

3. INDICATIONS

4. CONTRAINDICATIONS

5. PREVENTION

6. PREINDUCTION ASSESSMENT

7. METHODS

8. MONITORING

9. PAIN RELIEF

10.COMPLICATIONS

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1. DEFINITIONS Induction of labour: IOL

initiation of contractions in a pregnant woman who

is not in labour to help her achieve a vaginal birth

within 24 to 48 hs.

Successful induction

vaginal delivery within 24 to 48 hs of induction of

labour.

Elective induction

induction of labour in the absence of acceptable

fetal or maternal indications.

Cervical ripening

use of pharmacological or other means to soften,

efface, or dilate the cervix to increase the

likelihood of a vaginal delivery. Aboubakr Elnashar

Tachysystole

5 C/10 m period averaged over 30 m.

further subdivided into two categories

one with and one without FHR changes.

Hypertonus

Excessive uterine contractions lasting > 120 sec

without FHR changes.

This term should be abandoned and has been

replaced by tachystole without FHR changes.

Hyperstimulation

Excessive uterine contractions (tachysystole or

hypertonus) with abnormal FHR changes.

This term should be abandoned and has been

replaced by tachystole with FHR changes.

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2. SETTING AND TIMING

I. Outpatient:

If safety & support procedures are in place.

Should be audited continuously. (NICE, 2008)

Not recommended for improving birth outcomes.

(who, 2011)

II. Inpatient :

In the morning

{higher maternal satisfaction}.

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3. INDICATIONS 1. Must be documented:

reason for induction

method of induction

risks, including failure to achieve labour and

possible increased risk of CS.

(III-B)

2. If IOL is unsuccessful:

indication and method of induction should be

re-evaluated. (III-B)

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3. IOL should not be performed solely for

suspected f macrosomia. (III-D)

4. IOL should not be performed solely because of

patient or care provider preference. (III-D)

IOL is indicated when the risk of continuing the

pregnancy, for the mother or the fetus, exceeds

the risk associated with IOL

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I. High Priority

•• Preeclampsia ≥ 37 ws

•• Significant mat dis not responding to tt

•• Significant but stable APHge

•• Chorioamnionitis

•• Suspected fetal compromise

•• Term PLROM with maternal GBS colonization

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II. Other Indications

•• Postdates (> 41+0 w) or post-term (> 42+0 w)

•• Uncomplicated twin pregnancy ≥ 38 w

•• D M (glucose control may dictate urgency)

•• Alloimmune disease at or near term

•• IUGR

•• Oligohydramnios

•• Gestational hypertension ≥ 38 w

•• IUFD

•• PROM at or near term, GBS negative

•• Logistical problems (history of rapid labour, distance to hospital)

•• IUFD in a prior pregnancy (To alleviate parental anxiety, but

there is no known medical or outcome advantage for mother or baby.)

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Unacceptable Indications

•• Care provider or patient convenience

•• Suspected f macrosomia (EFWt > 4000 gm) in a non-diabetic

{no reduction in the incidence of shoulder dystocia but twice

the risk of CS}.

IOL at term is not recommended for suspected f

macrosomia (WHO, 2011) Gestational diabetes

IOL not recommended before 41 w (WHO, 2011).

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Maternal request

IOL should not routinely be offered.

However, under exceptional circumstances

at or after 40 w (NICE, 2008).

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Breech presentation

•IOL is not generally recommended.

•IOL:

1. ECV is unsuccessful, declined or contraindicated

2. Woman refused elective CS

3. Delivery is indicated

after discussing the associated risks with the woman. (NICE, 2008)

Fetal growth restriction

If severe, IOL is not recommended. (NICE, 2008)

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POST-DATE S INDUCTION

IOL between 41+0 and 42+0 w

{reduce perinatal mortality and meconium

aspiration syndrome without increasing CSR}. (I-A)

IOL is not recommended in women with an

uncomplicated pregnancy at gestational age less

than 41 w. (WHO, 2011)

Women who chose to delay induction > 41+0 w

should undergo twice-weekly assessment for fetal

well-being. (I-A)

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4. CONTRAINDICATIONS •• placenta or vasa previa or cord presentation

•• abnormal fetal lie or presentation

(e.g. transverse lie or footling breech)

•• prior classical or inverted T uterine incision

•• significant prior uterine surgery (e.g. full thickness myomectomy)

•• active genital herpes

•• pelvic structural deformities

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5. PREVENTION OF INDUCTION

Routine antenatal US for confirmation of EDD

has been shown to reduce induction rates for

postdates (> 41+0 w) pregnancies after correction

of dates

US in 1st T confirm gestational age.

(I-A)

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Routine sweeping (stripping) of membranes

promotes the onset of labour: decreases

induction rates.

{increase of local production of prostaglandins}. insertion of a digit past the internal cervical os

followed by 3 circumferential passes of the digit:

separation of the membranes from the lower

segment.

An adjunct to IOL rather than an actual method of

IOL.

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When?

1. Prior to IOL

2. At 40& 41 w in nulliparous

3. At 41 w in parous

4. When a vag exam is carried out to assess the

cervix

5. labour does not start spontaneously. (NICE, 2008)

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Massaging around the cervix in the vaginal

fornices

when the cervix was closed, a massage of the

cervical surface with the forefinger and middle

finger for 15 to 30 seconds .

±achieve a similar effect. (NICE, 2008)

Informed consent should be obtained &

documented.

discomfort and pain

possibility of bleeding postprocedure

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Quality assurance programs and induction

policies:

safety tools such as checklists, to ensure that IOL

are performed only for acceptable indications. (II-2B)

An induction committee.

To review each request and enforce the use of

proper indications for induction.

: Reduction in the number of elective inductions

The effect of coitus on promoting labour:

unclear.

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6. PRE-INDUCTION ASSESSMENT

1. Fetal well-being (CTG)

before administration of misoprostol.

for 30 m after administration of misoprostol

for 60 m after any tachysystole.

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2. Bishop score

To determine the likelihood of success and

To select the appropriate method of induction. (II-2A)

The Bishop score should be documented.

(III-B)

Induction of women with an unfavourable

cervix is associated with a higher failure rate in

nulliparous patients and a higher CS rate in

nulliparous and parous patients. (II-2A)

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Factors influencing success rates of

induction 1. Bishop score

2. Parity (prior vaginal delivery)

3. BMI

4. Maternal age

5. EFW

6. DM.

Elevated BMI (> 40 kg/m2)

Maternal age > 35 y

EFW > 4 kg

DM: increase the CS rate when labour is induced.

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Burnett modified scoring

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Initial studies were limited to parous women, but

the score was later found also to be applicable to

nulliparous women

The most important:

Cervical dilatation, followed by

Effacement,

Station, and

Position,

with the least important being Consistency.

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> 6: predictive of a successful vaginal delivery.

0 to 3: highest risk of failed induction and CS in

both nulliparous and parous

4 to 6: significantly higher risk of CS than those

with spontaneous labour.

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US of the cervix to predict successful labour induction: conflicting results. Rozenberg et al. reported that the Bishop score was a better predictor of time interval from induction to delivery. Fetal fibronectin and TVS predict successful induction, but neither have been shown to be superior to the Bishop score.

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7. METHODS FOR CERVICAL RIPENING/INDUCTION

A. UNFAVOURABLE CERVIX

I. Mechanical Options

Foley catheter with and without extra-amniotic

saline infusion that apply pressure on the internal os of

the cervix: stretch the lower uterine segment: increase

release of local PG.

Balloon catheter is recommended for IOL. (WHO, 2011)

The combination of balloon catheter plus oxytocin

is recommended as an alternative method of IOL

when PG (including misoprostol) are not available

or are contraindicated (WHO, 2011)

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Contraindications:

Absolute:

Low-lying placenta

Relative:

Antepartum hge

ROM

Lower tract genital infection. (NICE, 2008)

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Steps:

No. 18 Foley is introduced under sterile technique

into the intracervical canal past the internal os.

The bulb is inflated with 30 to 60 cc of water.

The catheter is left in place until either it falls out

spontaneously or 24 hs have elapsed.

Some practitioners apply a small degree of

traction on the catheter by taping it to the inside of

the leg.

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Advantages:

Simple

Reversible

Reduction in excessive uterine activity

low cost

Not associated with increased rates of

•maternal infection (chorioamnionitis and endometritis)

or

•neonatal infection. (SOGC, 2013)

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Foley catheter Vs PG:

•• an increased need for oxytocin

•• much less uterine tachysystole.

•• does not reduce the rate of CS from that of PG.

Intracervical Foley catheters

acceptable agents (II-2B)

safe both in the setting of

•vaginal birth after CS (I-B)

•outpatient setting. (II-2B)

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Double lumen catheters may be considered a second-line alternative. (II-2B)

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II. PHARMACOLOGICAL OPTIONS

1. PGE2

(cervical and vaginal): effective agents of cervical

ripening and IOL for an unfavourable cervix. (I)

PGE2 reduce CSR of women with an unfavourable

cervix: greater maternal satisfaction.

Vag E2 are preferred to intracervical

{:more timely vaginal deliveries}. (I)

Care must be taken to avoid the insertion of the higher dose of vaginal PGE2 (2 mg) into the cervical canal. •• Uterine tachysystole without FHR changes is more common

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PGE2 (cervical and vaginal) should not be used in

the setting of VBAC {increased risk of uterine

rupture}. (II-2D)

Vaginal PGE2 may be considered with ROM at

term and can be used in this setting. (I-A)

PGE2 in the setting of ROM had more maternal but

no more neonatal infections.

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•Regimens:

one cycle of vaginal PGE2 tablets or gel: one dose,

followed by 2nd dose after 6 h if labour is not

established (up to a maximum of 2 doses)

one cycle of vaginal PGE2 controlled-release pessary: one dose over 24 h. (NICE, 2008)

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II. Misoprostol

only in IUFD or in the context of a clinical trial (NICE, 2008).

Misoprostol can be considered a safe and effective

agent for IOL with intact membranes and on an

inpatient basis. (I-A)

Misoprostol should not be used in the setting of

vaginal birth after CS

{increased risk of uterine rupture}. (II-3D)

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Duration of action Onset of action Route

∼2 h 8 min Oral *

∼3 h 11 min Sublingual

∼4 h 20 min Vaginal

∼4 h 100 min Rectal

* After oral administration, uterine tonus develops, which is not

followed by uterine contractions, unless repeated doses are given

Pharmacokinetic Profiles: Key Facts

(Tang et al., 2007)

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•• 50 mcg orally with a drink of water (ensure that it

is swallowed quickly to avoid sublingual absorption)

or

25 mcg vaginally.

•• Repeat/4 h as long as contractions are absent or

non-painful. (SOGC, 2013)

Oral misoprostol (25 μg, 2-hourly)

vaginal misoprostol (25 μg, 6-hourly)

(WHO, 2011)

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•• The lower vaginal dose (25 mcg) tends to need

more oxytocin stimulation and the higher vaginal

dose (≥ 50 mcg) tends to have more uterine

tachysystole.

•• All doses of misoprostol can cause uterine

tachysystole.

The oral and vaginal routes have a similar

reduction of CS rates.

The oral route needs more oxytocin stimulation but

the vaginal route will have more tachysystole.

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•• Misoprostol Vs PGE2

More effective to achieve vaginal delivery

less epidural use

More uterine tachysystole.

•• PGE1 and PGE2 both reduce CS rates in an

unfavourable cervix.

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IUFD

Support {cope emotional& physical consequences}

Immediate IOL or expectant management:

• Woman is physically well

• Membranes are intact

• No evidence of infection or bleeding

Immediate IOL

• Ruptured membranes

• Infection or bleeding

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Method & dose: •Oral mifepristone followed by vag PGE2 or vag misoprostol.

•The choice & dose of vag PG depend on:

Clinical circumstances

Availability of preparations

local protocol.

•Previous CS {risk of uterine rupture is increased}:

dose of vag PG should be reduced

In 3rd T, in women with a dead or an anomalous

fetus, oral or vaginal misoprostol are recommended for

IOL

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Oxytocin can be started

30 m after removal of a dinpoprostone insert

(Cervidil)

6 h after gel (Prostin, Prepidil).

4 h after the last dose of misoprostol. (III-B)

(SOGC, 2013)

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B. FAVOURABLE CERVIX

1. Amniotomy

should be reserved for women with a favourable

cervix. Particular care should be given in the case

of unengaged presentation

{risk of cord prolapse}. (III-B)

After amniotomy, oxytocin should be commenced

early in order to establish labour. (III-B)

Amniotomy alone is not recommended for IOL. (WHO, 2011)

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•• Amniotomy creates a commitment to delivery

and should be

performed when the indication is convincing

documented.

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2. Oxytocin Example of low-dose protocol: Initial dose of oxytocin..................................1 to 2 mU/min

Increase interval......................................................30 minutes

Dosage increment....................................................1 to 2 mU

Usual dose for good labour.........................8 to 12 mU/min

Maximum dose before reassessment.................30 mU/min

Example of high-dose protocol: Initial dose of oxytocin..................................4 to 6 mU/min

Increase interval............................................15 to 30 minutes

Dosage increment...........................................4 to 6 mU/min

Usual dose for good labour.........................8 to 12 mU/min

Maximum dose before reassessment.................30 mU/min

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Term PROM

Oxytocin should be considered before expectant

management. (I-A)

If GBS +ve: start oxytocin as early as possible

after ROM in order to establish labour within 24 h. (III-B)

Both high- and low-dose oxytocin may be

considered. (III-B)

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Because of the various concentrations, oxytocin

infusion rates should always be recorded in

mU/m rather than mL/h. (III-L)

Oxytocin induction maybe considered in the

hospital setting of vaginal birth after CS. (II-3B)

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Practice Points

•• With PROM, oxytocin stimulation is more

effective than expectant management: reduce

maternal infection and increase vaginal deliveries

within 24 h, but it may increase CS rate.

•• In the setting of PROM, women preferred

oxytocin induction over expectant management.

•If PG are not available, IV oxytocin alone should

be used for IOL (WHO, 2011)

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8. MONITORING

1. CTG: When contractions begin

Once CTG is confirmed as normal: intermittent auscultation

2. Bishop score

-6 h after vag PGE2 tab or gel, or 24 h after vag PGE2

controlled-release pessary

-If a woman returns home after insertion of vag PGE2 tablet or

gel, she should be asked to contact her obstetrician:

when contractions begin

if she has had no contractions after 6 h.

3. Maternal & fetal monitoring Once active labour is established

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9. PAIN RELIEF

Inform woman:

•IOL is likely to be more painful than spontaneous

labour.

•The availability of pain relief options :

Simple analgesics

Epidural analgesia.

Support

labour in water .

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10. COMPLICATIONS

I. Ut hyperstimulation (tachystole with FHR

changes).

Tocolysis should be considered

Betamimetics are recommended

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II. Failed induction

Define:

labour not starting after one cycle of tt

Management

Support.

CTG

Maternal condition

a. Further attempt to induce labour or

b. CS

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III. Cord prolapse

Prevention:

•Before induction, engagement of the presenting part

should be assessed.

•Palpate for umbilical cord presentation during the

preliminary vaginal examination

•Avoid dislodging the baby’s head.

•Amniotomy should be avoided if the baby’s head is

high.

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IV. Uterine rupture

If uterine rupture is suspected during IOL:

emergency CS

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Thank

You Aboubakr Elnashar