Cervical Ripening and Induction of Labour: Everything You Need to Know

You’re past your due date and your baby isn’t coming. You feel no contractions and the clock is ticking. This is when your doctor may start talking to you about labour induction. Or more specifically, cervical ripening. Here’s what every expectant mum needs to know about cervical ripening. What Is Cervical Dilation or Ripening Cervical ripening (or cervical effacement) is one of the most common forms of labour induction (or IOL). The term is also oftentimes used interchangeably with IOL. Doctors perform them on mothers who are not able to dilate naturally. The process involves softening or ‘ripening’ the cervix medically, mechanically, or surgically to induce contractions and hence, dilation of the cervix. Normally, the cervix will dilate on its own through the action of natural prostaglandins when the baby is ready to come. However, sometimes the levels of this hormone are not enough to trigger dilation. A complete dilation of the cervix should be nothing less than 10cm. Anything less than that and labour induction may be performed. So, a doctor will step in and perform cervical ripening. A successful cervical ripening will result in uterine contractions and eventually, labour. When Is Cervical Ripening Necessary Over 20% of expectant mothers will require some form of labour induction. About half that number will involve the use of cervical ripening agents such as Misoprotol. Cervical ripening is required anytime an expectant mother has an IOL (indication of induction of labour). This is when the doctor decides it is better for the health of both mother and child if a labour induction is performed. The main criteria for an indication of IOL includes: post-term/prolonged pregnancy premature rupture of membranes hypertensive disorders of pregnancy (e.g. preeclampsia) gestational diabetes oligohydramnios One of the most common reasons why your doctor may recommend cervical ripening (or other forms of labour induction) is postmaturity. This is when your baby is past their due date. Overdue pregnancies are not only dangerous for the baby but the mother as well. So, a doctor will prescribe cervical ripening to induce labour. But other reasons also factor in, such as the mother’s preference. One of the ways that a doctor determines whether a mother needs cervical ripening is with something called a Bishop score. This method determines if the rate of dilation is sufficient for successful labour. The score works by differentiating between a ‘favourable’ cervix or an ‘unfavourable’ cervix. This will advise the doctor about the best method to employ for each mother when it comes to labour induction. The Bishop score is also used to measure the success of artificial ripening. If the dilation is not sufficient, the doctor may administer another round of ripening medication or try another method of labour induction. Mothers who have had multiple children are usually able to dilate faster than new mothers who are having their first child. What Are the Methods of Cervical Ripening There are various methods of cervical ripening. But the two main categories include mechanical ripening and pharmacological induction. Mechanical induction involves manual ripening of the cervix, usually through catheters. If your water hasn’t broken, then a doctor may also perform artificial rupture of the membranes (AROM) or amniotomy. Pharmacologic methods include the administration of cervical ripening medication. Examples include dinoprostone, misoprostol and oxytocin. Contrary to popular belief, ripening doesn’t always have to occur at the cervical area only such as with a gel or tablet suppository. Oral and intravenous medication are also available. Both dinoprostone and misoprostol are prostaglandins commonly used for cervical ripening and labour induction. There are pros and cons to both mechanical and pharmacological methods. The mechanical method is the safest, as it reduces the risk of dangerous side effects. However, it can also be quite uncomfortable. The pharmacological method, such as with oral, intravenous or suppository medication, is less invasive. But it may come with certain side effects. However, mechanical methods, while safer, may be less effective than pharmacological methods. Moreover, the process of using a Foley catheter to dilate the cervix requires an expert hand to get right. And the right doctors may not always be available to perform the procedure. However, in truth, no ripening method is superior or better than another. Is Cervical Ripening Safe? Just like any medical procedure, cervical ripening comes with some risks. The cervical ripening drug, Misoprostol, for instance, comes with various side effects. Some of these include diarrhoea, nausea, vomiting, cramps and fever. Drug-induced cervical ripening can also cause uterine hyperstimulation. This is where the uterus experiences excessive contractions, which may stress out or even endanger the baby. Doctors will always take into account various factors before administering cervical ripening. This includes the mother’s medical history, age, weight and others. But possibly the greatest and most dangerous risk of cervical ripening is uterine tachysystole. This condition is hyperstimulation of the uterus that can cause excessive and uncontrollable contractions that will not only endanger the mother but the baby as well. The main risk for the baby is that it will reduce the supply of oxygen in the womb, causing the baby’s blood to be acidic. The risk to the mother can include cervical laceration, haemorrhage and placental rupture. Only pharmacological induction can cause uterine tachysystole. I.e., the use of cervical ripening drugs. Mechanical induction will never cause excessive contractions. Some factors that make a mother more prone to experiencing this condition are: younger maternal age nulliparity (never given birth to a child, even if they’ve miscarried in the past) chronic hypertension a history of smoking, alcohol or drug use. Preeclampsia, oligohydramnios, and a long labour duration can also predispose a mother to uterine tachysystole. Is Cervical Ripening Painful? Depending on the method used to soften the cervix, your level of discomfort may vary. The actual sensation of your cervix dilating from the ripening process can be painful. As uterine contractions increase, your cervix will continue to dilate. However, the process of ripening itself may also be uncomfortable. Pharmacological methods, which involve the use of labour induction medication like prostaglandins are the least invasive. Oral medication is the most preferred method of cervical ripening. You take several doses of Misoprostol tablets until your cervix dilates. However, the symptoms, as mentioned earlier, can be challenging. Vaginal administration, which can come in the form of a suppository, or gel, may be uncomfortable as well but not painful. Finally, mechanical methods, which are the earliest and oldest forms of labour induction. These are not only uncomfortable but painful as well. Mechanical methods involve using a catheter, such as a Foley catheter. The doctor will insert a tube into the cervix and then inflate it with saline solution. This balloon stretches open the cervix, encouraging it to soften and dilate. This process can be both uncomfortable and painful. Another method of labour induction is called amniotomy. If your water hasn’t already broken, then the doctor will insert a small hook to rupture the membranes and release the amniotic fluid. This may trigger the dilation process and is relatively painless. What is the Success Rate of Cervical Ripening There is an 80% success rate of cervical ripening, which means that most of the time it is very effective in facilitating vaginal delivery. However, even with these odds, it is very rare that cervical ripening is successful on the first try. Even favourable cervixes need time before they fully dilated for labour. Cervical ripening is mostly a waiting game. For instance, a dose of Misoprostol must be given every 4 hours. If no contractions occur or dilation is unsuccessful, the doctor will administer another dose. Sometimes cervical ripening can take as long as 12 to 24 hours. For unfavourable cervixes, the process may be even longer. One study found that age and weight play an important role in a successful IOL. If the mother is over a certain age (typically 35) and has a BMI of over 30, there is a greater chance that cervical ripening will fail. Another study found that being of a certain height (less than 70 inches) may also be a risk factor of failed IOLs. Nulliparous women (who have not been pregnant or given birth in the past) were also more likely to experience a failed IOL than multiparous women (women who have had at least one successful pregnancy and vaginal delivery). The next factor is premature rupture of membranes. If you’ve already had your water broken, then there is a higher chance that IOL may not work. However, even if you do not experience any of these factors, there is no way of guaranteeing that you will have a successful labour induction. What Happens If Cervical Ripening Doesn’t Work? There are cases where labour induction or cervical ripening does not work. Even after multiple attempts and with different methods, a cervix may fail the Bishop score and not be sufficiently dilated to allow for a natural vaginal birth. As mentioned, overdue babies are more likely to experience or cause complications during delivery. A medical professional will define a failed induction of labour as failure to achieve the minimum Bishop score 24 hours after administration of cervical ripening treatments. That is the cervix failed to dilate adequately within that window of time. However, other factors are also taken into account. This includes strength and frequency of contractions, rupture of membranes, and the state of the baby. In some cases, even after an amniotomy, the mother will not dilate. This is when the doctor will recommend a Caesarean birth. A Caesarean delivery involves surgically removing the baby from the abdomen as opposed to a vaginal birth. The surgery will be performed under an anaesthesia of the mother’s choice. As Caesarean deliveries are high risk procedures, many doctors will try to avoid them unless completely necessary. Preparing the Way For Birth There are so many challenges that await an expectant mother. And cervical ripening is just one of them. But with the advancement of medicine, we have more methods now to ensure a safe and painless dilation process. This way, a smooth labour can be guaranteed with minimal risk to either mum or baby. You've got this, mummy; here's to a smooth and safe delivery! Disclaimer: The information provided in this article is for informational purposes only and should not be considered as medical advice from Motherhood. For any health-related concerns, it is advisable to consult with a qualified healthcare professional or medical practitioner. For more insightful stories and fun recipes, stay tuned to Motherhood Story!

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