Induction of labour

IOL indications and recommendations - summary

Prolonged pregnancy

Establishing the estimated due date (EDD)

Pregnancy cannot be said to be prolonged without accurate dating.

An accurate EDD should be established when pregnancy care commences.

If the last normal menstrual period (LNMP) was certain and menstruation regular, use the table below to establish an agreed EDD.

If the LNMP was not certain, or menstruation irregular, use an EDD estimate from an ultrasound performed between six and 24 weeks.

Preventing prolonged pregnancy

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

To avoid the risks associated with prolonged pregnancy, women with uncomplicated pregnancies should be offered IOL between 41+0and 42+0 weeks.

The exact timing of IOL should take into account the woman's preferences and local health service organisational circumstances.

Pre-labour rupture of membranes at term (Term PROM)

IOL is appropriate within 24 hours of term PROM.

Timing of IOL may also be influenced by local conditions; for example, some health services will prefer to commence IOL when staffing levels are optimal for managing an oxytocin infusion.

In the following circumstances, IOL should be commenced as soon as possible after PROM:

• the woman is GBS positive
• meconium stained liquor
• abnormal CTG not requiring immediate delivery
• suspected maternal sepsis.

See: PROM

See also: Group B streptococcus sepsis (GBS) prevention for neonates

Preterm pre-labour rupture of membranes (PPROM)

If a woman has PPROM before 34 weeks, IOL should not be carried out unless there are additional obstetric indications (for example, infection or fetal compromise).

If a woman has PPROM after 34 weeks, the decision to undertake IOL should consider the balance of risks and benefits for the woman and baby and the local availability of Special Care or Neonatal Intensive Care nursery facilities.

See: PPROM

See also: Preterm labour

Previous caesarean section

If delivery 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 a Bishop Score <6 at the time of IOL, is associated with an increased risk of uterine scar rupture in labour, compared with women who labour spontaneously.

The risk of uterine scar rupture is lower with the use of mechanical cervical ripening (balloon catheter) than with the use of prostaglandins or oxytocin.

When undertaking IOL after a previous caesarean section, the woman should be informed of the:

• increased risk of uterine rupture
• increased risk of the need for emergency caesarean section during labour.

Maternal request

IOL should not routinely be undertaken for maternal request alone.

However, 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 her cervix is favourable and the fetal head fixed in her pelvis.

Breech presentation

See Breech presentation: diagnosis and management

In most circumstances, caesarean delivery will be planned for breech presentations. However, where clinical circumstances are favourable for a vaginal breech delivery and the woman wishes to have a vaginal birth, IOL may be offered.

As with all vaginal breech births, clinicians must consider the availability of resources at their health service, including:

• availability of clinicians who are skilled and experienced in breech delivery
• ability to provide continuous fetal monitoring and clinicians skilled and experienced in CTG interpretation
• immediate availability of caesarean facilities.

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.

Suspected fetal macrosomia

In the absence of any other indications, IOL should not be carried out for suspected fetal macrosomia (usually defined as an estimated fetal weight >4000 g).

Advanced maternal age

There is an increased risk of perinatal mortality in women over 35 years of age.

There has been expert opinion suggesting that IOL at 39 weeks could reduce the risk of perinatal mortality in this cohort. However, no high level evidence has been found to support IOL for advanced maternal age as an isolated risk factor.

Ethnicity

There is a growing body of research on peripartum complications and interventions associated with ethnicity, maternal country of birth and migration status. Of particular relevance for the Australian context, researchers have found an increased risk of late-pregnancy stillbirth, GDM, SGA and intrapartum caesarean for fetal compromise in women of south Asian ethnicity.

Research to date is limited by variation in methodology and in classification of ethnicity, making it difficult to generalise. The consistent message is that further studies are needed to determine the mechanism underlying observed differences in outcomes. Therefore, there is not sufficient evidence at this time to recommend IOL timing based on maternal country of birth as an isolated risk factor.

Obesity

See Obesity during pregnancy, birth and postpartum

The optimal timing of delivery for obese women may be influenced by the presence of co-morbidities, such as diabetes or preeclampsia. In the absence of co-morbidities, there is an absence of evidence to guide recommendations about the timing of delivery. That said, there is substantial evidence that the risk of stillbirth is raised in obesity, with particularly concerning risks of late gestation stillbirth, exacerbated in women with BMI >50.

Clinicians should discuss the benefits and risks of IOL at 39-40 weeks with all women above their healthy weight range. For women with a BMI ≥50 delivery is recommended at 38-39 weeks.

Other complications of pregnancy

Some of the other indications for IOL include:

• abnormal CTG
• abnormal US, including oligohydramnios, polyhydramnios and abnormal Doppler studies
• suspected or diagnosed fetal growth restriction
• decreased fetal movements
• antepartum haemorrhage (APH)
• hypertensive disorders
• gestational diabetes
• intrauterine fetal death (FDIU)
• history of previous stillbirth
• maternal medical conditions
• maternal mental health condition.

Women presenting with any of these complications will require management based on their individual clinical circumstances.

• Malpresentation: transverse or oblique lie, footling breech, brow.
• Previous classical uterine incision or previous caesarean section of unknown type.
• Cord presentation.
• Abnormal fetal surveillance (CTG or ultrasound) requiring immediate delivery.
• Placenta praevia or vasa praevia.
• Primary genital herpes infection at time of delivery or within six weeks of EDD.
• Cervical carcinoma.
• Any other contraindication to labour or vaginal birth.

Communication

Treatment and care should take into account women's individual needs and preferences.

Women who are being offered or undergoing IOL should have an opportunity to make informed decisions about their care and treatment in partnership with the clinicians providing their care.

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, care and information provided should be culturally appropriate. It should also be accessible to women, their partners, support people and families and take into account any specific needs, such as physical or cognitive disabilities or limitations to their ability to understand spoken or written English.

Download the Patient information sheet on IOL

Planning for care beyond 41 weeks

During pregnancy care, women should be informed that most women will go into labour spontaneously by 42 weeks.

At their 38-week antenatal visit, all women should be offed information about the risks associated with pregnancies that last longer than 41 weeks. All of the options should be discussed:

• Expectant management.
• Membrane sweeping:
  • membrane sweeping makes spontaneous labour more likely and reduces the need for medical or mechanical IOL for prolonged pregnancy
  • they may experience discomfort during membrane sweeping and bleeding afterwards.
• IOL between 41+0 and 42+0 weeks. When IOL is recommended, clinicians should explain and document the following:
  • indication for IOL
  • risks and benefits of IOL in this clinical context
  • when and where IOL will take place
  • proposed method of IOL
  • plan for fetal monitoring
  • options for support and pain relief during IOL
  • possibility of and course of action if IOL is unsuccessful
  • an alternative plan for ongoing care and assessment if the woman chooses not to have an IOL at this time.

Clinicians recommending IOL should also:

• allow the woman time to discuss the information with her partner and/or support person before coming to a decision
• invite the woman to ask questions and explore her options
• support the woman in whatever decision she makes
• document discussions and decisions reached.

When IOL is declined

If a woman chooses not to have an IOL, her decision should be respected. In partnership with the woman, clinicians should then make a plan for ongoing management.

From 41+3 weeks, women following a course of expectant management should be offered increased monitoring consisting of at least twice-weekly CTG, with or without ultrasound estimation of amniotic fluid index (AFI).

The following should be documented in the woman's hospital medical record and (where applicable) her hand-held medical record:

• Indication for recommended IOL
• Discussion of risks and benefits
• Discussion of the woman's questions about IOL
• Plan for where and when IOL will take place
• Proposed methods of IOL
• The woman's consent to IOL (where applicable)
• Plan for expectant management if the woman declines IOL
• Consultation, referral or escalation

Victorian Maternity Record

Download the IOL booking form

Membrane sweeping

Membrane sweeping (also commonly referred to as a 'stretch and sweep') 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 a method of induction.

Clinicians should always ensure that there is no evidence of a low-lying placental site before membrane sweeping.

• Before 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 (such as 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 subsequent chorioamnionitis is likely to be small.
• Women should be informed of potential discomfort and pain during a membrane sweep and the potential for bleeding post-procedure, before consent is obtained.

Artificial rupture of membranes (ARM, amniotomy)

ARM may be used alone or in combination with oxytocin therapy to induce labour.

The decision to perform ARM and await onset of contractions may be considered when the cervix is favourable and there is a past history of rapid labour, grand multiparity, previous lower segment caesarean section or when the mother has expressed a 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 ARM is usually not necessary.

Prostaglandin E2 (PGE2) Vaginal Gel (Prostin®)

Prostaglandin E2 (PGE2) Vaginal Gel (Prostin®) is used to promote cervical ripening (softening and effacement) and to stimulate myometrial contractions.

The use of PGE2 for IOL on an unfavourable cervix (Bishop score <6) decreases the likelihood of failed induction and prolonged labour and increases the chance of spontaneous vaginal birth.

Dosage

Precautions

• Bishop score must be ≤5 at the time of insertion.
• PGE2 Vaginal Gel (Prostin®) must not be inserted into the cervical canal.
• To reduce the risk of uterine hyperstimulation:
  • oxytocin (Syntocinon®) should not be commenced within six hours of PGE2 Vaginal Gel (Prostin®) being inserted
  • ARM should not be performed within 4 hours of PGE2 Vaginal Gel (Prostin®) being inserted.
• Physiological management of third stage is contraindicated when labour is induced.

Insertion

• Ensure the woman has an empty bladder.
• Ask the woman to lie flat with her feet on the bed in a modified lithotomy position.
• Insert the PGE2 Vaginal Gel (Prostin®) into the posterior fornix of the vagina, avoiding the cervical canal.
• The woman should remain in a lateral position for at least 30 minutes after insertion.

Dinoprostone (PGE2) continuous release vaginal pessary (Cervidil®)

Dinoprostone (PGE2) continuous release vaginal pessary (Cervidil®) is used to promote cervical ripening (softening and effacement) and stimulate myometrial contractions. The use of PGE2 for IOL on an unfavourable cervix (Bishop score <6) decreases the likelihood of failed induction and prolonged labour and increases the chance of spontaneous vaginal birth.

Dosage

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

Precautions

• Bishop score must be ≤5 at the time of insertion.
• Dinoprostone (PGE2) continuous release vaginal pessary must not be inserted into the cervical canal.
• To reduce the risk of uterine hyperstimulation:
  • oxytocin (Syntocinon®) should not be commenced with Dinoprostone (PGE2) continuous release vaginal pessary (Cervidil®) in situ or within 30 minutes of removal
  • ARM should not be performed with Dinoprostone (PGE2) continuous release vaginal pessary in situ.
• Physiological management of third stage is contraindicated when labour is induced.

Insertion

• Ensure the woman has an empty bladder.
• Ask the woman to lie flat with her feet on the bed in a modified lithotomy position.
• Remove the continuous release vaginal pessary from the foil packaging. Tear the foil top and gently pull the product out of the sachet. Do not use sharp instruments that may damage the product.
• Insert the pessary high into posterior vaginal fornix, using only a small amount of water-soluble lubricant and avoiding the cervical canal.
• Once inserted, tuck any excess tape gently into the vagina, leaving enough exposed to facilitate retrieval.
• The woman should remain in a lateral position for at least 30 minutes after insertion.

Removal

The pessary should be removed quickly by gentle traction on the retrieval tape when the following occurs:

• spontaneous rupture of membranes
• regular, painful 3 minutely contractions, irrespective of cervical change
• uterine hyperstimulation
• abnormal CTG
• maternal adverse effects such as nausea, vomiting, hypotension or tachycardia
• at least 30 minutes prior to commencing an intravenous oxytocic infusion
• insufficient cervical ripening in 24 hours.

Note: on removal, the pessary will have swollen to two to three times its original size. It should be disposed of as clinical waste.

Balloon catheter

Balloon catheters can be used for mechanical cervical ripening (softening and effacement), applying pressure on the internal os of the cervix and increasing the release of endogenous prostaglandins. Balloon catheters for cervical ripening are associated with reduced rates of uterine hyperstimulation and tachysystole, reduced rates of instrumental birth due to fetal distress, and fewer neonatal intensive care admissions.

Double balloon catheters (DBCs): Cooks & Atad, for example, are available and licensed for use in labour induction. Current evidence does not point to DBCs having an advantage over single balloon catheters (SBCs) in relation to type of birth, length of labour or maternal/neonatal complications. DBCs, however, are more expensive.

Insertion instructions below relate to Foley catheters.

Equipment

• 16F or 18F Foley single balloon catheter - SBC (or Cooks & Atad DBC)
• Sterile speculum and light source
• Ring forceps

Insertion

• Ensure the woman has an empty bladder.
• Insert the Foley bulb into the internal cervical os - this can be done digitally or visually using a speculum and ring forceps.
• Fill the balloon with 30ml of sterile water.
• Tape the catheter to tension on the woman's medial thigh.

Removal

The Foley catheter can be removed by deflating the balloon and applying gentle traction:

• at 12-24 hours after insertion (no difference in outcome has been observed with a 24-hour ripening time compared to 12 hours)
• at spontaneous rupture of membranes
• at onset of labour
• when there is hyperstimulation or fetal distress.

The balloon may be expelled spontaneously due to cervical dilatation.

Outpatient cervical ripening

Sending women home after insertion of prostaglandins or balloon catheters is an uncommon practice in Australia. However, available evidence suggests that outpatient cervical ripening with balloon catheters may be a safe and acceptable option for women with uncomplicated pregnancies, who have reliable means of communication and transport.

Oxytocin (Syntocinon®)

Labour can be induced or augmented using intravenous oxytocin (Syntocinon®).

Precautions

• If the cervix is unfavourable (Bishop score <6), vaginal prostaglandins or balloon catheter should be considered.
• Oxytocin (Syntocinon®) to induce labour in women with a history of previous caesarean should be discussed with the lead obstetrician prior to use.
• Oxytocin (Syntocinon®) should not be used within 6 hours of prostaglandin E2 (PGE2) Vaginal Gel (Prostin®).
• Oxytocin (Syntocinon®) should not be used with Dinoprostone (PGE2) Continuous Release Vaginal Pessary (Cervidil®) in situ or within 30 minutes of its removal.
• Oxytocin (Syntocinon®) to augment labour in a multiparous woman should be discussed with the lead obstetrician prior to use, particularly when the woman has an epidural for analgesia.
• Physiological management of third stage is contraindicated in women receiving oxytocin to induce or augment labour.

Equipment

• Standard volume infusion - volumetric pump, IV tubing, Y extension set, IV pole and tapes.
• Low volume infusion - syringe driver, IV tubing, Y extension set, IV pole and tapes, 60 ml syringe.
• 10 units of oxytocin (Syntocinon®).
• Sodium chloride 0.9% or Compound Sodium Lactate (CSL, Hartmann's Solution).
• CTG.

Preparing and administering oxytocin (Syntocinon®)

• Ensure that a CTG has been performed prior to administration of oxytocin (Syntocinon®).
• Ensure continuous CTG monitoring throughout oxytocin (Syntocinon®) infusion.

Standard volume infusion: NOT SUITABLE FOR WOMEN NEEDING FLUID RESTRICTION

• Add 10 units of oxytocin (Syntocinon®) to a 1000 ml bag of Compound Sodium Lactate (Hartmann's Solution) or normal saline.
• Label the bag and sign entries on the woman's Intravenous Fluid Orders chart.

Standard volume infusion:

Commence the oxytocin (Syntocinon®) infusion at 2 milliunits/min (12 ml/hr) via a volumetric infusion pump 

Low volume infusion: SUITABLE FOR ALL WOMEN

• Add 10 units (1 ml) of oxytocin (Syntocinon®) to 49 ml of sodium chloride 0.9% (total volume = 50 ml) in a 60 ml syringe.
• Label the syringe and sign entries on the woman's Intravenous Fluid Orders chart.

Low volume infusion:

Commence the oxytocin (Syntocinon®) infusion at 2 milliunits/min (0.6 ml/hr) via a syringe driver

Practice points

• Once labour is established in a multigravida, consider slowly reducing the infusion rate at 30 minutes or greater intervals, being careful to maintain four contractions in 10 minutes and ensuring 60 seconds of resting tone between contractions.
• An additional IV side line is unnecessary unless it is indicated for an epidural infusion, patient-controlled epidural analgesia (PCEA), patient-controlled analgesia (PCA) or hydration.
• The oxytocin (Syntocinon®) infusion should not normally be stopped during procedures (insertion of an epidural), as long as high quality CTG monitoring can be continued.
• Increase the rate every 30 minutes (per increment schedule below), aiming for four contractions in 10 minutes, lasting 40-90 seconds, with 60 seconds of resting tone between contractions.
• Once four contractions in 10 minutes are achieved, maintain the infusion rate.
• Titrate the infusion rate as required, to maintain four contractions in 10 minutes, lasting 40-90 seconds, with 60 seconds of resting tone between contractions.
• Once the maximum has been reached and a further increase in the infusion rate is required, it must be discussed with the midwife in charge and lead obstetric clinician.

See the RANZCOG Intrapartum Fetal Surveillance Guideline - 3rd edition for further information on CTG monitoring during oxytocin induction/augmentation.

Prostaglandin PGE1 (PGE1) pessaries, oral tablets and solution, buccal, sublingual, vaginal and rectal tablets (Misoprostol)

PGE1 tablets (Misoprostol) have most commonly been used, off label, for termination of pregnancy and IOL in the setting of fetal death in utero (FDIU).

Although emerging research suggests that Misoprostol may be a safe and effective method of labour induction for women with intact membranes, the evidence is not yet sufficient to recommend this as routine practice.

Download the IOL management QRA flowchart

Maternal assessment

• Document baseline vital signs:
  • blood pressure
  • pulse rate
  • respiratory rate
  • temperature.
• Note any vaginal loss.
• Perform an abdominal palpation and note:
  • fetal lie
  • presentation
  • engagement of fetal head
  • uterine activity over a 10-minute period.
• Vaginal examination and Bishop score, to confirm method of induction.

Fetal surveillance

A CTG must be performed prior to commencement of IOL:

• a normal CTG should be demonstrated within 6 hours prior to insertion of prostaglandins PGE1 or PGE2, without change in the clinical situation
• a normal CTG should be recorded prior to the commencement of intravenous oxytocin infusion.

When IOL is indicated in the presence of CTG abnormalities, the lead obstetrician must be consulted prior to commencement of induction.

Maternal assessment

Cervical ripening

• Remain with the woman for the first 10 minutes, observing the CTG and palpating uterine activity.
• If the first 10 minutes of CTG is reassuring, review the woman and the CTG intermittently; at LEAST every 10 minutes.
• 50 minutes after insertion, record:
  • vital signs:
    • blood pressure
    • pulse rate
    • respiratory rate
    • temperature
  • vaginal loss
  • palpated uterine activity over a 10-minute period
  • CTG report.
• The woman may ambulate as desired 30 minutes after Prostin® or Cervidil® insertion, if the CTG monitoring is normal.
• After the initial hour, record:
  • half-hourly vaginal loss
  • hourly uterine activity, palpated over a 10-minute period.
• After 3 hours, if there are no contractions detected and no fetal concerns, cease frequent observations.
• 6 hours after Prostin®, a vaginal examination can be performed to reassess the Bishop score.
• 12 to 24 hours after Cervidil®, remove the pessary if still in situ and reassess the Bishop score.

Oxytocic infusion

Palpate and record uterine activity for a 10-minute period every 30 minutes.

Correlate palpated strength of contraction with the woman's perception of contraction strength.

Offer support and analgesia accordingly.

Record the rate of oxytocic infusion in mls/hr at the beginning of each set of observations in the woman's medical record and on the CTG.

Fetal surveillance

Cervical ripening

• Continuous CTG until a normal trace (as per RANZCOG criteria) is observed.
• After the initial hour, auscultate the fetal heart rate (FHR) half-hourly for three hours.
• Recommence CTG if:
  • FHR abnormalities are auscultated
  • the woman reports uterine activity (CTG may be subsequently discontinued if the CTG is normal and the woman is not in labour. If uterine activity persists but labour is not established, perform a CTG two-hourly)
  • labour is established
  • spontaneous rupture of membranes.

Oxytocic infusion

• Continuous CTG monitoring is indicated from the commencement of oxytocic infusion.
• The following should be noted on the CTG contemporaneously:
  • infusion rate
  • correlation of detected and palpated uterine activity
  • colour of liquor
  • vaginal examination findings
  • maternal pulse rate, particularly when there is uncertainty about differentiation between maternal and fetal heart rates
  • abnormal maternal vital signs
  • maternal position changes
  • fetal movements.

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 fetal wellbeing should be reassessed.

Subsequent management options include:

• a further attempt to induce labour - the timing should take into account the clinical situation and the woman's preferences

OR

• caesarean section.

Uterine hyperstimulation

See RANZCOG Intrapartum Fetal Surveillance Guideline 

Cord prolapse

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:

• Assess engagement of the presenting part by abdominal palpation and confirm by vaginal examination.
• Palpate for umbilical cord presentation during the preliminary vaginal examination and avoid dislodging the baby's head.
• Avoid amniotomy if the baby's head is high and mobile.

Other potential complications/emergencies

• Uterine rupture
• Abnormal CTG
• Hypersensitivity reactions
• Vaginal irritation
• Placental abruption
• Gastrointestinal disturbances
• Amniotic fluid embolism
• Postpartum haemorrhage
• Genital oedema

Available evidence does not support the following methods of IOL:

Audit and performance improvement

All maternity services should have processes in place for:

• auditing clinical practice and outcomes
• providing feedback to clinicians on audit results
• addressing risks, if identified
• implementing change, if indicated.

Below is a link to a template that can be used by any maternity service to audit the following IOL parameters: Indications, Outcomes and Standard of Care.

Induction of labour audit template

For further information on using this tool or assistance with auditing, please contact us: maternityehandbook@safercare.vic.gov.au.

References

Background

• Clinical Practice Guidelines: Antenatal care - Module I. Commonwealth of Australia (2012).
• Clinical Practice Guidelines: Antenatal care - Module II. Commonwealth of Australia (2014).
• Victoria's Mothers, Babies and Children 2012 and 2013. Section 1: Findings and recommendations. DHHS (2016a).
• Victoria's Mothers, Babies and Children 2012 and 2013: Section 2: Data, tables and figures. DHHS (2016b).
• Intrapartum Fetal Surveillance: Clinical Guideline - Third edition 2014. RANZCOG (2014).
• Different methods for the induction of labour in outpatient settings. Cochrane Database of Systematic Reviews.
• Herpes simplex in pregnancy (2015) King Edward Memorial Hospital Clinical Guidelines.

IOL - International clinical guidelines

• Inducing labour: Clinical guideline. National Institute for Health and Care Excellence (NICE) (2008).
• Induction of Labour: Clinical Practice Guideline. SOCG (2013) JOGC 2013; 35(9): 840-857

Balloon catheters

• Labor induction in nulliparous women with an unfavourable cervix: double balloon catheter versus dinoprostone. Suffecool, K. et. al. (2014) Journal of Perinatal Medicine 2014; 42(2): 213-218. doi: 10.1515/jpm-2013-0152
• Cost-effectiveness of induction of labour at term with a Foley catheter compared to vaginal prostaglandin E2 gel (PROBAAT trial). van Baaren, GJ. et. al. (2013) BJOG 2013; 120: 987-995. doi: 10.1111/1471-0528.12221
• Intracervical Foley balloon catheter for cervical ripening and labor induction: A review. Greenberg, V. & Khalifeh, A. (2015) Seminars in Perinatology 39 (2015) 441-443
• Foley Catheter for Induction of Labor at Term: An Open-Label, Randomized Controlled Trial. Gu, N. et. al. (2015) PLoS ONE 10(8): e0136856. doi: 10.1371/journal.pone.0136856
• Balloon catheters for induction of labour at term after previous cesarean section: a systematic review. Kehl, Weiss & Rath (2016) European Journal of Obstetrics & Gynecology and Reproductive Biology 204: 44-50. doi: 10.1016/j.ejogrb.2016.07.505
• Management of prolonged pregnancy by induction with a Foley catheter. Kruit, H. et. al. (2015) ACTA Obstetricia et Gynecologica 2015; 94: 608-614. doi: 10.1111/aogs.12632

Breech

• Induction of labor in breech presentations at term: retrospective observational study. Macharey et.al. (2016) Arch Gynecol Obstet (2016) 293: 549-555. doi: 10.1007/s00404-015-3853-4

Advanced maternal age

• Randomized Trial of Labor Induction in Women 35 Years of Age or Older. Walker et.al. (2016) The New England Journal of Medicine 374: 813-822. doi: 10.1056/NEJMoa1509117

Caesarean section

• Caesarean section rates and adverse neonatal outcomes after induction of labour versus expectant management in women with an unripe cervix: a secondary analysis of the HYPITAT and DIGITAT trials. Bernares, TP. et. al. (2016) BJOG 2016; 123: 1501-1508. doi: 10.1111/1471-0528.14028
• Does induction of labour increase the risk of caesarean section? A systematic review and meta-analysis of trials in women with intact membranes. Wood, Cooper & Ross (2013) BJOG 121: 674-685. doi: 10.1111/1471-0528.12328
• Use of labour induction and risk of caesarean delivery: a systematic review and meta-analysis. Mishanina et.al. (2014) CMAJ 186;9: 665-673. doi: 10.1503/cmaj.130925

Prostaglandins

• Labour induction with prostaglandins: a systematic review and network meta-analysis. Alfirevic, Z. et. al. (2015) BMJ 2015; 350: h217 doi: 10.1136/bmj.h217

Ethnicity

• Migration to western industrialised countries and perinatal health: A systematic review. Gagnon, A.J. et. al. (2009). Social Science & Medicine 2009;69: 934-946. doi: 10.1016/j.socscimed.2009.06.027
• Ethnic differences in stillbirth and early neonatal mortality in The Netherlands. Ravelli, A.C.J. et. al. (2011) Journal of Epidemiology & Community Health 2011; 65: 696-706. doi: 10.1136/jech.2009.095406
• Maternal racial origin and adverse pregnancy outcome: a cohort study. Khalil, A. et. al. (2013) Ultrasound in Obstetrics & Gynecology 2013; 41: 278-285. doi: 10.1002/uog.12313
• Racial variation in the association between gestational age and perinatal mortality: prospective study. Balchin, I. et. al. (2007) BMJ doi: 10.1136/bmj.39132.482025.80
• Ethnicity and the risk of late-pregnancy stillbirth. Drysdale, H. et. al. (2012) MJA doi: 10.5694/mja12.10125
• Maternal Asian ethnicity and obstetric intrapartum intervention: a retrospective cohort study. Reddy, M. et. al. (2017) BMC Pregnancy and Childbirth doi: 10.1186/s12884-016-1187-2

Outpatient IOL

• Auckland Consensus Guideline on Induction of Labour.
• Outpatient Foley catheter versus inpatient prostaglandin E2 gel for induction of labour: a randomised trial (2013). Biomed Central.
• Improving induction of labour - a quality improvement project addressing Caesarean section rates and length of process in women undergoing induction of labour (2015). BMJ Quality Improvement Reports.
• Outpatient induction of labour in low risk women: A best practice toolkit (2015) NHS.
• Outpatient versus inpatient cervix priming with Foley catheter: A randomized trial (2017). European Journal of Obstetrics & Gynecology and Reproductive Biology.