Maternity & Newborn Clinical Network Induction of Labour – Victorian standard

Victorian Standard for Induction of Labour

Acknowledgement

We gratefully acknowledge the clinical expertise of the Maternity and Newborn Clinical Network Induction of Labour Expert Clinical Advisory Group. We also thank the National Institute of Clinical Excellence (NICE) for their permission to use their IOL Guideline1, which forms the basis of this document and the Mercy Hospital for Women, Southern Health and the Royal Women’s Hospital for sharing components of their Induction of Labour (IOL) Guidelines.

Rationale for the standard

This Victorian Standard for IOL has been prepared by the Maternity Newborn Clinical Network (MNCN) with the objective of providing Maternity Service providers in Victoria with an agreed Standard of Care based on the best currently available evidence.

Individual Maternity Services are encouraged to use the Standard as the basis for reviewing, or developing their own Clinical Practice Guideline (CPG) that take into account the specific conditions (eg access to and staffing of operating theatres), applying to their own service. Example CPG’s are included.

Because of the movement of maternity service staff between health services, it is strongly recommended that where at all possible, variation between practices, especially for drug regimens, should be avoided.

Introduction

Induced labour has an impact on the birth experience of women. It may be less efficient and may be more painful than spontaneous labour. Epidural analgesia and assisted birth are more likely to be required than for spontaneous labour.

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IOL is a relatively common procedure. In 2005 and 2006, 17,000 or 25% of labours in Victoria were induced. This includes induction for all medical reasons. When labour was induced 60% of women gave birth without further intervention, with 18% having instrumental births and 20% having emergency caesarean section2. Although some of these interventions may be related to the indication for induction, it is likely that there is a contribution from IOL itself. IOL, as with all clinical interventions, should be clinically justified, weighing the risks of the induction against those of continuing the pregnancy.

IOL is usually more consuming of healthcare resources than spontaneous labour. Obligatory intrapartum fetal surveillance, managing oxytocin infusions, longer periods of ‘observed’ labour and increased need for operative birth all add to the workload. When planning inductions of labour, hospitals should take into account the requirement for additional resources and plan staffing accordingly.

These standards offer best practice advice on the care of women who are undergoing or being recommended an IOL.

1. Informed Consent

Treatment and care should take into account women’s individual needs and preferences. Women who are having or being offered IOL should have the opportunity to make informed decisions about their care and treatment in partnership with their clinicians.

Good communication between clinicians and women is essential. It should be supported by evidence-based written information tailored to the needs of the individual woman. Treatment and care, and the information women are given, should be culturally appropriate. It should also be accessible to women, their partners and families, taking into account any additional needs such as physical or cognitive disabilities, and limitations regarding their ability to understand written or spoken English.

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At full term, around the 38-40 week antenatal visit, all women should be offered information about the risks associated with pregnancies that last longer than 41 weeks, and their options. The information should cover:

• membrane sweeping:

− what membrane sweeping is

− that, on average, membrane sweeping makes the onset of spontaneous labour sooner more likely, which may reduce the need for formal IOL to prevent prolonged pregnancy in some women

− that discomfort and vaginal bleeding are possible from the procedure

• IOL is recommended between 41+3 and 42+0 weeks

• recommendations for fetal surveillance prior to IOL or the onset of spontaneous labour

Clinicians should explain the following points to women in whom IOL is recommended:

• the reasons for induction being recommended

• when, where and how induction could be carried out

• the arrangements for support and pain relief

• the alternative options if the woman chooses not to have IOL at this time

• the risks and benefits of IOL in specific circumstances and the proposed induction methods

• the possibility that the IOL may be unsuccessful and what options are available (see section 7.2)

• this information should be made available where possible in the woman’s own language

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Clinicians recommending IOL should:

• allow the woman time to discuss the information with her partner before coming to a decision

• encourage the woman to look at a variety of sources of information

• invite the woman to ask questions, and encourage her to think about her options

• support the woman in whatever decision she makes

2. Establishing the Estimated Due Date (EDD)

Pregnancy cannot be said to be prolonged without accurate dating of the pregnancy.

• if early ultrasound (<14 weeks) is available the estimated due date (EDD) should be calculated from the ultrasound, overriding calculation of the EDD using the last known menstrual period (LNMP)

• if ultrasound performed >14 weeks, the EDD should be calculated from the LNMP unless the ultrasound differs by more than one week

• for women with oligomenorrhoea, lactational amenorrhoea or oral contraceptive withdrawal bleeding where a calculation cannot be based on the LNMP, then the first ultrasound should be used to determine the EDD

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3. Contraindications to Induction of Labour

• malpresentation: transverse or oblique lie, footling breech, brow

• previous classical uterine incision or previous caesarean section of unknown type

• cord presentation

• abnormal fetal surveillance (eg CTG) requiring immediate delivery

• placenta praevia or vasa praevia

• active genital herpes

• cervical carcinoma

• or any other contraindication to labour or vaginal birth

3.1 Require lead obstetrician discussion

• frank breech

• previous caesarean section

• severe intrauterine growth restriction

• cardiotocographic non-reassuring fetal status

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4. Methods of induction

4.1 Membrane sweeping

Membrane sweeping involves the examining finger passing through the cervix to rotate against the wall of the uterus, to separate the chorionic membrane from the decidua. If the cervix will not admit a finger, massaging around the cervix in the vaginal fornices may achieve a similar effect. For the purpose of this standard, membrane sweeping is regarded as an adjunct to IOL rather than an actual method of induction. Clinicians should always check that there is no evidence of a low-lying placental site before membrane sweeping:

• prior to formal IOL, women may be offered a vaginal examination for membrane sweeping

• at the 40 and 41 week antenatal visits, nulliparous women may be offered a vaginal examination for membrane sweeping

• at the 41 week antenatal visit, multiparous women may be offered a vaginal examination for membrane sweeping

• when a vaginal examination is carried out to assess the cervix, the opportunity may be taken to offer the woman a membrane sweep

• additional membrane sweeping may be offered if labour does not start spontaneously

• in some circumstances, (eg Group B Strep (GBS) carriage), the clinician may choose not to recommend membrane sweeping prior to IOL. There is insufficient evidence to define infection rates in women who are GBS positive, with and without membrane sweeping but the number of cases of consequent chorioamnionitis is likely to be small

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4.2 Artificial rupture of membranes (ARM, amniotomy)

Artificial rupture of membranes may be used alone or in combination with oxytocin therapy. Oxytocin therapy should not be commenced within 6 hours of insertion of prostaglandin gel.

The decision to perform ARM and await onset of contractions may be considered when there is a past history of rapid labour, grand multiparity, previous lower segment caesarean section or when the mother has expressed strong preference for giving some time to await spontaneous labour after ARM.

The preferred instrument is an amniotomy hook. Alligator or other toothed forceps should not be used unless the ARM is technically difficult. The practice of obtaining fetal hair to confirm membrane rupture is usually not necessary.

4.3 Oxytocin

A standardised regimen is recommended and attached (see Oxytocin (Syntocinon®) Induction and Augmentation of Labour CPG).

Prior to commencement of oxytocin:

• forewater rupture confirmed, in some circumstances it is reasonable to commence oxytocin first and then perform the ARM

• > 6 hours should have elapsed since Dinoprostone PGE2 vaginal gel administration

• > 30 minutes should have elapsed after removal of Dinoprostone ® PGE2 continuous release pessary (Cervidil )

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4.4 Vaginal prostaglandin preparations

PGE2 vaginal preparations are used to promote cervical ripening (softening and effacement) and stimulate myometrial contractions to enable IOL.

Contraindications

• Bishop score ≥ 6

• abnormal CTG or known severe fetal compromise

• persisting maternal temperature

• vaginal bleeding

• known hypersensitivity to PGE2 or any constituents of the gel

• spontaneous labour

Relative Contraindications (may be used with caution under lead obstetrician supervision)

• multiparous women particularly grand multiparity (>5)

• previous uterine hyperstimulation

• previous caesarean section

• ruptured membranes

• mobile presenting part

• asthma

• cardiac disease

• multiple pregnancy

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4.4.1 Prostaglandin E2 vaginal gel

A standardised regimen is recommended and an example is

attached (see IOL with Prostaglandin E2 (PGE2) Vaginal Gel (Prostin®) Clinical Practice Guideline). Bishop score should be

reassessed 6 hours after vaginal PGE2 gel insertion to monitor progress.

Women with otherwise uncomplicated pregnancies and a

satisfactory CTG tracing post PGE2 insertion, who return home, should be asked to contact her maternity service when contractions begin or if her membranes break, and otherwise represent for review by 6 hours post insertion.

4.4.2 Prostaglandin E2 continuous release vaginal pessary (Cervidil®)

A standardised regimen is recommended and an example is

attached (see IOL with Dinoprostone (PGE2) Continuous Release Vaginal Pessary (Cervidil®) Clinical Practice Guideline). Bishop score should be reassessed 24 hours after

vaginal PGE2 continuous release pessary insertion, to monitor progress.

Each pessary contains 10mg dinoprostone (PGE2) and releases a mean dose of approximately 4 mg over 12 hours (0.3 mg/hr).

The pessary should be removed from the freezer immediately prior to insertion (pre-warming is not required).

The pessary should be placed high into the posterior vaginal fornix using only a small amount of water soluble lubricant avoiding the cervical canal.

The woman should remain semi recumbent or lateral for at least 30 minutes.

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Remove pessary when:

• spontaneous rupture of membranes

• onset of labour

• uterine hyperstimulation or hypertonic contraction(s)

• abnormal CTG

• suggestive maternal adverse effects such as nausea, vomiting, hypotension or tachycardia

• at least 30 minutes before starting oxytocin infusion

• insufficient cervical ripening in 12 - 14 hours

4.5 Cervical ripening balloon catheter

Mechanical devices are not recommended for routine IOL except in the context of clinical trials.

5. Fetal Surveillance

Wherever IOL is carried out, facilities should be available for continuous electronic fetal heart rate (FHR) and uterine contraction monitoring3.

Before IOL is commenced, the Bishop score should be assessed and recorded, and a normal FHR pattern should be confirmed using electronic fetal monitoring (EFM).

Procedure:

The CTG should be observed continuously for the first 10 minutes with review every 10 minutes. In the last 10 minutes of the “initial” hour the woman should be observed again continuously for timing of uterine activity and fetal heart reactivity.

Intrapartum fetal surveillance should be performed as described in RANZCOG Intrapartum Fetal Surveillance Clinical Guidelines May 2006. Note that both oxytocin administration and the onset of contractions after the use of prostaglandins are indications for continuous EFM.

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If the FHR is abnormal after administration of vaginal PGE2, recommendations on management of fetal compromise as per RANZCOG Intrapartum Fetal Surveillance Clinical Guidelines May 2006.

Once active labour is established, maternal and fetal monitoring should be carried out as described in RANZCOG Intrapartum Fetal Surveillance Clinical Guidelines May 2006.

6. Induction of labour in specific circumstances

6.1 Prevention of prolonged pregnancy

Women with uncomplicated pregnancies should be given every opportunity to go into spontaneous labour.

Women with uncomplicated pregnancies should usually be recommended IOL between 41+3 and 42+0 weeks to avoid the risks of prolonged pregnancy. The exact timing should take into account the woman’s preferences and local health services organisational circumstances.

6.2 Supporting a woman’s decision to decline induction of labour

If a woman chooses not to have IOL, her decision should be respected. Clinicians should discuss the woman’s care with her from then on. From 41+3 weeks, women who decline IOL should be offered increased antenatal monitoring consisting of at least twice-weekly cardiotocography with or without ultrasound estimation of maximum amniotic pool depth. Where performed, if the AFI (amniotic fluid index) is <5 then IOL should again be recommended to the woman.

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6.3 Prelabour rupture of membranes at term (“Term PROM”)

Women with prelabour rupture of membranes at term (at or over 37 weeks gestation) should be counselled regarding the risks and benefits of IOL versus expectant management. IOL would generally be recommended within 24 hours of term PROM. Some health services will prefer to commence oxytocin in these women at a time when staffing levels are optimal for managing an oxytocin infusion.

Health Services should also have a policy regarding the use of antibiotics. [NICE Clinical Guideline Intrapartum Care]

6.4 Previous caesarean section

If birth is indicated, women who have had a previous caesarean section may be offered IOL, repeat caesarean section or expectant management on an individual basis, taking into account the woman’s circumstances and wishes.

It is important to recognise that IOL in women with a previous caesarean section, particularly in those with Bishop Score <6 at the time of induction, is associated with an increased risk of scar rupture in labour. Therefore, ideally IOL in women with a previous caesarean section should be either avoided or undertaken when the cervix is Bishop Score ≥ 6 allowing an ARM ± oxytocin. If induction is required in the setting of an unfavourable cervix then this should be undertaken using vaginal prostaglandins. Women should be informed of the following risks with IOL:

• increased risk of need for emergency caesarean section during induced labour

• increased risk of uterine rupture

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6.5 Maternal request

IOL should not routinely be offered on maternal request alone. It is accepted that some women may have exceptional personal circumstances where her request for earlier IOL may be considered at or after 39 weeks, particularly if the cervix is favourable and the head is fixed in the pelvis.

6.6 Breech presentation

In most circumstances, a caesarean section will be recommended in situations where birth is indicated and the fetus is presenting by the breech. However, where clinical circumstances are favourable for a vaginal breech delivery and the woman wishes to have a vaginal birth, IOL may be offered, after discussing with the woman the relative benefits and risks.

6.7 History of precipitate labour

IOL to avoid a birth unattended by clinicians should not be routinely offered to women with a history of precipitate labour.

7. Complications of Induction of Labour

7.1 Uterine hyperstimulation (tachysystole)

Defined as:

• four or more contractions in 10 minutes over a 30 minute period

OR

• contractions lasting more than 2 minutes in duration

OR

• contractions of normal duration occurring within 60 seconds of each other

Hyperstimulation may occur with or without FHR changes.

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All maternity units should have a management guideline for uterine hyperstimulation and an example is provided in management of uterine hyperstimulation (tachysystole) clinical practice guideline.

7.2 Unsuccessful induction of labour

If induction does not result in labour, clinicians should discuss this with the woman and provide support. The woman’s condition and the pregnancy in general should be fully reassessed, and fetal wellbeing should be assessed using electronic fetal monitoring.

Subsequent management options include:

1. a further attempt to induce labour - the timing should depend on the clinical situation and the woman’s wishes

OR

2. caesarean section

7.3 Cord prolapse at time of amniotomy

To reduce the likelihood of cord prolapse, which may occur at the time of amniotomy, the clinician should ensure that the following precautions are taken prior to the procedure:

• engagement of the presenting part is assessed by abdominal palpation and confirmed by vaginal examination

• should palpate for umbilical cord presentation during the preliminary vaginal examination and avoid dislodging the baby’s head

• amniotomy should be avoided if the baby’s head is high and mobile

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8. Methods that are not recommended for induction of labour

8.1 Pharmacological methods

The following should not be used for IOL:

• intravenous prostaglandin E2

• extra-amniotic prostaglandin E2

• intracervical prostaglandin E2

• intravenous oxytocin alone

• hyaluronidase

• corticosteroids

• oestrogen

• vaginal nitric oxide donors

8.2 Non-pharmacological methods

Clinicians should inform women that the available evidence does not support the following methods for IOL:

• herbal supplements

• acupuncture

• homeopathy

• castor oil

• hot baths

• enemas

• sexual intercourse

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Resources

1. Oxytocin (Syntocinon®) Induction and Augmentation of Labour Clinical Practice Guideline

® 2. Induction of Labour with Prostaglandin E2 (PGE2) Vaginal Gel (Prostin ) Clinical Practice Guideline

3. Induction of Labour with Dinoprostone (PGE2) Continuous Release Vaginal Pessary (Cervidil®) Clinical Practice Guideline

4. Management of Uterine Hyperstimulation (Tachysystole) Clinical Practice Guideline

References

Note: Full reference list for NICE CG 70 and 55 are available from evidence tables and associated references.

1. NICE Clinical Guideline 70: Induction of Labour July 2008 www.nice.org.uk

2. Davey M-A, Taylor O, Oats JJN, Riley M. Births in Victoria 2005 and 2006, Victorian Perinatal Data Collection Unit, Statewide Quality Branch, Department of Human Services, August 2008, Melbourne

3. RANZCOG Intrapartum Fetal Surveillance Clinical Guidelines May 2006

4. NICE Clinical Guideline 55: Intrapartum Care June 2008 www.nice.org.uk

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