Induction of labour - Is it right for me?
What is induction of labour?
An induction of labour is when a doctor or midwife uses various methods to artificially initiate or accelerate labour. such as:
Membrane stretch and sweep
Pessary or gel or tampon
Artificial Rupture of Membranes (ARM)
Synthetic hormone drip
Foleys catheter
Dilapin rods
A membrane stretch and sweep
This is when a doctor or midwife sweeps their finger around the opening of the cervix to stimulate labour. A sweep is when the doctor or midwife carefully separates the membranes that surround the baby from their cervical attachment. It is not recommended to perform a stretch and sweep before 40+ weeks and if the cervix is unfavourable . This method of induction is not always effective in starting spontaneous labour so it may be offered again or it may lead to the choice of having a pessary (or gel) containing prostaglandin inserted into the vagina to help ripen the cervix and stimulate contractions.
A pessary or gel containing prostaglandin or a tampon with propress
This may be offered if a membrane stretch and sweep is not effective at initiating spontaneous labour. This method of induction is when a tampon shaped pessary or tablet or gel is inserted vaginally in an attempt to ripen the cervix and to stimulate contractions. This is one of the most commonly recommended ways to induce labour.
The artificial rupture of membranes,
This is also known as AROM or breaking the waters, is often used to accelerate labour after other induction methods have initiated contractions or after spontaneous labour has begun. Note: waters do not always break, as is often shown on film and tv, to signify the beginning of labour. Many women reach full dilation before they have a Spontaneous Rupture of Membranes (SROM) with some even birthing the baby in ‘the caul’ (the amniotic sac).
Foleys Catheter
A Foley Catheter is a thin, soft, flexible silicone tube (catheter) with a small, inflatable balloon at one end. Sometimes its called a Foley balloon, a cervical ripening balloon, or a Cook catheter. It works by creating gentle, sustained pressure on the inside of the cervix, mimicking the pressure of a baby's head. A doctor or midwife inserts the catheter through the vagina and into the cervix, usually during a vaginal exam. Once the balloon is through the cervix but outside the amniotic sac, it is inflated with sterile saline solution. The balloon is roughly the size of a ping-pong ball when fully inflated (approx. 30–60 ml). The tube hangs outside the vagina and is often lightly taped to the inside of the thigh, The pressure of the balloon on the cervix triggers the body to produce natural hormones called prostaglandins, which soften the cervix and promote dilation. The catheter stays in place for up to24 hours. It typically falls out on its own when the cervix has opened to approximately 3–4 cm.
Dilapan Rods
Dilapan-S rods are a non-pharmacological, mechanical method used for cervical ripening (softening, thinning, and opening the cervix) to induce labour. They are small, sterile, matchstick-sized rods made of a synthetic hydrogel (AQUACRYL) that act as an osmotic dilator, expanding as they absorb moisture from the cervix to prepare it for birth. The rods are inserted into the cervix. Within 12–24 hours, they absorb fluid, expanding from a thin 4mm to a maximum width of roughly 15mm. This gradual, radial pressure mimics the body's natural preparation for labour. The pressure causes the cervix to release its own natural hormones (prostaglandins), which soften and ripen the cervix. Once the cervix is open enough, then AROM might be used or the body might go into natural labour, or a Syntocinon drip might still be required.
A hormone drip containing synthetic oxytocin (Syntocinon®)
This should only be offered if the membrane sweep or prostaglandins have not been effective in starting labour. It is also offered to women who may have been induced by membrane sweep or prostaglandins but whose contractions and cervical dilation have slowed completely or appear to have stopped. It is not recommended for use until at least 6 hours after receiving prostaglandin gel or 12 hours after removal of the prostaglandin pessary.
Whether to consent to induction of labour, or not, is a choice that at least 1 out of 2 women will have to make in her maternity care in Ireland. If an induction is clinically indicated, in the case of fetal and maternal risk such as: pre-eclampsia, fetal growth restriction, diabetes or problems with the placenta – then a woman may have less difficulty in agreeing with her maternity care provider that it is in her and her baby’s best interest to undergo an induction to minimise risk. Induction for serious medical conditions can be life saving.
For most other pregnant women, an induction may be suggested because there is a belief that the baby is too big or too small (known respectively as ‘large for dates’ or ‘small for dates’) OR clinical policy states that a woman must be induced after a certain number of days over their 40 week Estimated Due Date (EDD). The consensus on the window of normal gestation is that it can be anywhere from 37 to 42 weeks; however, some hospital policies will suggest induction of labour from 40 weeks, or earlier, depending on the perceived complication. In these cases the research shows that taking a ‘wait and see’ approach more often leads to spontaneous onset of labour, less interventions and a healthy outcome for both mother and baby. The difficulty is knowing when to consent to an induction or when to ‘wait and see’.
The following list of advantages and disadvantages to the various methods of induction of labour may be helpful in balancing the risks and making a choice whether to consent to the procedure, or to ‘wait and see’:
Membrane Stretch and Sweep Advantages
Does not involve medication and generally safe when there are no other complications
If it results in spontaneous labour, it may mean avoiding further interventions with other methods of induction such as syntocinon or prostaglandin
Can be performed at hospital or at home
Membrane Stretch and Sweep Disadvantages
Some women report pain and discomfort during a sweep
Can cause some bleeding and irregular contractions
Often has to repeated 2 to 3 times before other methods of induction are used
Prostaglandin Pessary Tampon or Gel Advantages
Increases the likelihood of vaginal birth within 24 hours
Reduced the need for syntocinon augmentation in labour
Prostaglandin Pessary Tampon or Gel Disadvantages
Risk of uterine hyperstimulation (with the pessary, not with gel)
May cause changes in fetal heart rate
Artificial Rupture of Membranes Advantages
Can be done in hospital or at home
May shorten labour
Artificial Rupture of Membranes Disadvantages
Evidence does not support routinely breaking the waters for women in normally progressing spontaneous labour
There is little evidence that a shorter labour has benefits for the mother or the baby
Foley’s catheter advantages
It allows the ripening process to begin without the use of synthetic hormonal medication (like Syntocinon).
It has a lower risk of overstimulating the uterus (uterine tachysystole) compared to hormonal methods.
It is considered a safe option for women attempting a Vaginal Birth After Cesarean(VBAC).
In many hospitals, if the mother and baby are doing well, the patient can go home while the catheter is in place
Foley’s catheter disadvantages
Insertion can be uncomfortable or cause cramping, similar to menstrual pain, but it is not usually severely painful.
There is a small risk of infection, similar to other vaginal examinations.
In some cases, the balloon may not cause enough dilation, necessitating a different method of induction
Dilapan Rods Advantages
Non-Medicinal: Unlike prostaglandin gels or pessaries (Propess), Dilapan contains no active drugs or hormones, reducing the risk of uterine overstimulation.
High Success Rate: Studies show roughly 4 out of 5 women achieve successful cervical ripening after the first round of Dilapan-S.
Comfort and Mobility: Because they do not cause intense contractions on their own, many women find them more comfortable than hormonal methods. Women can often walk around, sleep, and go to the toilet normally.
Outpatient Suitability: Due to their safety profile, they are frequently used for outpatient induction, allowing women to go home after insertion and return the next day for the next stage of labour.
Safer for TOLAC: Dilapan-S is often considered for women who have had a previous cesarean section (Trial of Labor After Cesarean - TOLAC), as it carries a lower risk of uterine rupture compared to pharmacological methods.
Dilapan Rods Disadvantages
Discomfort/Pain: Some cramping or pain may occur.
Minor Bleeding: Light spotting is common and usually not a concern.
Vasovagal Reaction: Some women experience temporary dizziness, nausea, or faintness during insertion or removal.
Expulsion: On rare occasions, the rods may fall out before the removal time
Hormone Drip with Syntocinon advantages
Can shorten labour
Is less likely to cause hyperstimulation than prostaglandins but can be controlled (by reducing the dosage or by switching off the drip altogether) if it does lead to tonic contractions
Hormone Drip with Syntocinon Disadvantages
Uterine hyperstimulation leading to much more frequent and painful contractions
Increased rate of other interventions such as electronic fetal monitoring or CTG trace, epidural analgesia, instrumental delivery and c-section
Increased risk of ‘overdosage’ leading to fetal distress
Implicated in poorer breastfeeding outcomes
Note: One of the main reasons for an syntocinon drip is slow progression of labour, sometimes referred to as dystocia or ‘failure to progress’. This is controversial as there are no definitive studies that accurately describe the length of ‘normal’ labour. Recent research does not support the original clinical indication for oxytocin augmentation of labour, namely that it was believed the need for operative delivery (either c-section, forceps or ventouse) is reduced by administering oxytocin drip. This is not supported by Cochrane Reviews
Complementary or Natural Methods of Induction include (there is no supported evidence of the following in the medical literature – See Mozurkewich et al.):
acupuncture and reflexology
castor oil
nipple stimulation
sexual intercourse
homeopathy
hypnobirthing
References
The following research links were used to compile the information in this article:
Bugg et al. Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour. Cochrane Pregnancy and Childbirth Group – Intervention Review. July 6, 2011. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD007123.pub2/full
Kelly et al. Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term. Cochrane Summaries. May 16, 2012. http://summaries.cochrane.org/CD003101/vaginal-prostaglandin-pge2-and-pgf2a-for-induction-of-labour-at-term
Mozurkewich et al. Methods of induction of labour: Systematic review. BMC Pregnancy and Childbirth 2011, 11:84. http://www.biomedcentral.com/content/pdf/1471-2393-11-84.pdf
National Collaborating Centre for Women’s and Children’s Health. Induction of labour. 2nd edition. London: RCOG Press; 2008. http://www.nice.org.uk/nicemedia/live/12012/41260/41260.pdf
Smyth et al. Amniotomy for shortening spontaneous labour. Cochrane Summaries. June 18, 2013. http://summaries.cochrane.org/CD006167/amniotomy-for-shortening-spontaneous-labour