Labor Induction Factors and Fetal Monitoring

Induction of Labour

• Induction of labour is the artificial initiation of labour before spontaneous onset
• It can be viewed as any procedure or intervention that starts labour rather than allowing it to commence spontaneously (Brodrick 2024).

Indications for Induction of Labour

• Maternal indications:

  • Prolonged or post-term pregnancy
  • Medical problems (e.g., diabetes, hypertension, cholestasis)
  • Poor obstetric history (previous stillbirth)
  • Prelabour rupture of membranes (>24 hours)
  • Advanced maternal age (Brodrick 2024)
  • Maternal request (consider after discussing benefits/risks)

• Fetal indications:

  • Suspected fetal compromise (e.g., IUGR)
  • Reduced fetal movement
  • Macrosomia
  • Rhesus isoimmunisation
  • Severe congenital abnormalities
  • Fetal death (NICE 2021, Brodrick 2024)

Prevention of Prolonged Pregnancy

• Explain that labour usually starts naturally by 42+0 weeks
• At 38-week antenatal visit, reconfirm preferences for birth and discuss options (expectant management, induction, planned caesarean)
• For uncomplicated singleton pregnancies, offer induction at 41+0 weeks, or soon after
• Women’s preferences, local circumstances, and identified risks will determine the timing
• (NICE 2008 updated 2021).

Prevention of Prolonged Pregnancy - Risks of Continuing Beyond 41+0 Weeks

• Increased likelihood of caesarean birth
• Potential increased likelihood of the baby needing admission to neonatal intensive care unit
• Potential increased likelihood of stillbirth and neonatal death
• Potential increased likelihood of assisted vaginal birth (forceps or ventouse)
• (NICE 2021) - Monitoring might consist of twice-weekly cardiotocography and ultrasound estimation of maximum amniotic pool depth(2008, amended 2021)

Prolonged Pregnancy (Post-Term)

• Often used interchangeably with postmaturity
• Prolonged pregnancy is one that exceeds 42 completed weeks or 294 days from LMP
• It refers to the duration of pregnancy, not a maternal condition
• Postmaturity describes the baby born after 42 weeks

Contraindications for Induction of Labour

• Placenta praevia or vasa praevia
• Oblique or Transverse lie
• Malpresentation (breech)
• Cord presentation or cord prolapse
• Severe fetal compromise (Brodrick 2024)

Assessment Before Induction

• Abdominally assess the level and stability of the fetal head in the lower part of the uterus at or near the pelvic brim
• Assess and record the Bishop score
• Confirm normal fetal heart rate pattern and absence of uterine contractions
• Ensure facilities are available for cardiotocography if induction of labour is started (NICE 2008, amended 2021).

Modified Bishop Score

• A method of assessing whether the cervix is favourable for induction
• Decide which method is suitable
• For women with a Bishop score of 6 or less offer induction with vaginal dinoprostone
• vaginal tablet, gel or controlled-release vaginal delivery system or with low dose( 25 microgram) oral misoprostol tablets (NICE 2021)

Monitoring After Induction

• When uterine contractions begin, assess fetal well-being and uterine actions with intrapartum CTG interpretation
• If CTG is normal, consider intermittent auscultation for low risk situations
• If abnormal fetal heart rate or excessive uterine contractions, stop additional doses and remove any vaginal pessaries/delivery systems
• Reassess Bishop score at appropriate intervals to monitor progress (NICE 2008, amended 2021).

Membrane Sweeping

• Might make labour more likely to start naturally
• Offer women a vaginal examination for membrane sweeping before formal induction of labour
• Consider additional membrane sweeping if labour does not start spontaneously, however discomfort and vaginal bleeding are possible (NICE 2008, amended 2021).

Alternative Methods of Labour Induction

• Herbal supplements, acupuncture, homeopathy, castor oil, hot baths, enemas, and sexual intercourse are not supported by current evidence (NICE 2008/2021).

Prostaglandins (PGE2)

• Locally acting chemical compounds used for ripening the cervix
• Available in gel or pessary form
• Most commonly administered vaginally in posterior fornix
• Contributes to uterine contraction
• Success rate of 30-50%
• Monitor fetal heart and contractions

Using Propess

• Slow release of prostaglandin over 24 hours
• Similar purpose – to soften cervix
• Assess maternal well-being
• Informed consent required
• Insert pessary to cervical canal, positioned behind posterior vaginal fornix to keep it in situ
• (NICE 2008, amended 2021)

When to Remove Propess

• When regular, painful contractions are established
• Spontaneous rupture of the membranes or amniotomy
• Suggestion of uterine hyperstimulation or hypertonic uterine contraction
• Evidence of fetal distress
• Evidence of maternal systemic adverse dinoprostone effects (e.g., nausea, vomiting, hypotension or tachycardia)
• At least 30 minutes before starting an intravenous infusion of oxytocin
• After 24 hrs if cervical ripening has not been achieved

Prostaglandin Regimen (Primigravida and Multiparous) - (See details in full reference file)

Risks Associated with Oxytocin

• Uterine hyper stimulation/hypertonus
• Fetal hypoxia/asphyxia
• Fluid retention
• Uterine rupture
• Amniotic fluid embolism
• Postpartum haemorrhage (PPH)
• Increased need for epidural analgesia
• Restricted mobility (NICE 2008, 2021)

WHO Recommendations on Induction of Labour

• Induction recommended at or beyond 41 weeks (>40+7 days) of gestation.
• Recommendation doesn't apply to situations where gestational age isn't reliably estimated.
• Potential need for women (post-term pregnancy) discussed in advance so questions, benefits and risks are understood
• Not recommended at gestational age less than 41 weeks. Insufficient evidence for uncomplicated pregnancies before 41 weeks.

Augmentation of Labour

• Accelaration of labour
• Methods:
• Amniotomy
• Syntocinon

Prelabour Rupture of Membranes at Term

• Accurate history (time, amount, colour, odour of liquor/vaginal loss)

• Note pain, discomfort, contractions, history of similar episodes, fetal movements

• Monitor and record all vitals

• General wellbeing, and abdominal examination to establish gestation, lie, position, presentation

• Auscultate fetal heart with Pinnards/Doppler, note uterine tenderness, note vaginal loss. Four-hourly observations (or sooner).

• Advise woman to report changes (wellbeing, flu-type symptoms, abdominal pain, tenderness, fetal movements)

• Speculum not necessary if liquor is visible.

Prelabour Rupture of Membranes at Term - Fetal Assessment

• Abdominal examination to estimate growth, position, presentation to exclude uterine tenderness

• CTG if criteria are met

• Ultrasound scan assessment of liquor (if required) to diagnose rupture and fetal wellbeing.

• Offer women with prelabour rupture of membranes choice of induction or expectant management (24 hours, consideration of IOL after 24 hrs, NICE 2008, updated 2021)

• Support woman's decision if they choose not to be induced, and discuss care options

• If woman has prelabour rupture (37+0+5 weeks), positive group B streptococcus - immediate induction/caesarean birth (NICE 2021)

IOL after Previous LSCS

• Advise previous LSCS women that uterine scar increases uterine rupture risk with induction.
• If IUFD and previous LSCS, follow recommendations for monitoring, and offer one-to-one midwifery care during labour and birth
• Dinoprostone and misoprostol contraindicated (NICE 2021)

IOL for IUD

• More than 85% of women with IUFD labour spontaneously within three weeks of diagnosis.
• Support the woman’s preferences regarding the timing of IOL
• Delaying IOL a few days is acceptable if membranes intact and no signs of infection (NICE, updated 2008).

IOL in Specific Circumstances

• Previous Caesarean section (avoid if classical incision)
• History of precipitate labour (not routinely offered)
• Fetal macrosomia without diabetes
• Consider maternal requests after discussing benefits and risks.

Outpatient Induction

• Consider outpatient induction (with vaginal preparations or mechanical methods) in women with uncomplicated conditions
• Ensure safety and support
• Agree a review plan with the woman before she returns home
• Schedule for observation/contact obstetrician/midwife when contractions start, if no contractions, ruptured membrane or other concerns arise (NICE 2008, amended 2021)

Role of the Midwife

• Planning: Good communication skills, information and informed consent, provide support
• Labour: Monitor maternal and fetal wellbeing, assess pain, assessment of progress, accurate record keeping

NICE Guideline - Summary

• Update to 2008 version recommends induction at 41 weeks.
• Woman's decision to not induce should be supported and care options discussed.
• Research shows higher infant mortality after 42 weeks without induction

Summary - NICE 2021 (IOL Overview)

• Explain reasons for induction, procedures, support/pain relief, alternatives if no induction, risks/benefits/induction methods
  • Discuss induction may not be successful and what woman's options would be.

IOL for Post-term

• By 40/40 weeks, 58% deliver, 74% by 41/40, 82% by 42/40
• Stillbirth incidence increases with gestation
• 18% may remain pregnant after 42/40 without induction.

This quiz covers key considerations for the timing of labor induction in uncomplicated singleton pregnancies. It explores factors influencing the risk of complications, advises women who opt out of induction, and verifies accurate statements regarding fetal monitoring. Understanding these aspects is crucial for informed decision-making during pregnancy.