Induction of labour is currently a topical issue in midwifery. This month, I am risking controversy by discussing my thoughts on the debate over increasing induction of labour. Over the past two years, I have noted in my clinical setting a reduction in the number of births in the midwifery led setting. I have often tried to understand this phenomenon, particularly with what actually feels like much higher rates of activity within the maternity unit. I audit the birth centre data and have noted a decline in the number of mothers attending the midwifery led setting each month.
On reviewing hospital policies and current evidence that may have affected this decline, I noticed the change in recommendations and guidelines for induction of labour for post-ter m pregnancies. It seems everyone is being induced. Despite there being an abundance of evidence that supports induction of labour in relation to reducing stillbirth rates, why do I sense that this is not the right path to be taking, yet again it is being medicalised as a normal physiological process. Is this another case of ‘too much too soon’ as described by Miller et al (2016) whereby the intervention, that is induction of labour, has been shown to improve outcomes by reducing the stillbirth rate, but potentially causes more harm when used indecorously or customarily.
Recent data from NHS maternity statistics reported a decrease in the number of persons going into spontaneous labour from 68.6% in 2007–2008 to 52.5% in 2017–2018 (NHS Digital, 2018). It is reported that induction of labour has increased from 20.4% in 2007–2008 to 32.6% in 2017–2018 with an increasing trend (NHS Digital, 2018). That amounts to nearly half of all pregnant persons being induced! The stillbirth rate during this time has reduced from 5.2 per 1 000 births in 2017 to 4.1 per 1 000 births in 2018, which represents 1 baby per 1 000 in a 10-year period. This does not support the increasing induction rates and therefore the issue must be more complex than simply inducing labour early to reduce mortality.
Hedegaard et al (2014) compared a more proactive induction of labour regime with expectant management (awaiting spontaneous onset of labour). The results of this study found a reduction in the stillbirth rate with a more proactive regime of recommending induction of labour (Hedegaard et al, 2014). However, this study was a national cohort study which had its limitations. It is open to selection and information bias, and it also collects data over a large span of 12 years during which both practices and the health of the population have changed. It is also worth noting that cohort studies cannot give a conclusive verification of a link between the intervention and risk.
A further study by Middleton et al (2018) compared induction of labour from 40-weeks gestation versus expectant management and, again, found a reduction in stillbirth rates with induction of labour. However, they also found an increase in instrumental births and the adverse outcomes as a result of instrumental birth was not investigated but requires consideration. Conversely, Grobman et al's (2018) randomised controlled trial of induction of labour for medically and obstetrically uncomplicated mothers at 39-weeks gestation, compared to expectant management, found no significant decrease in adverse perinatal outcomes. They did, however, find a reduction in caesarean section (c-section) but, as discussed by Sara Wickham (2015) in her online blog, human factors must also be taken into consideration and may play a part in earlier decisions for caesarean section when obstetricians are already concerned about the length of the pregnancy. Whereas with early induction of labour where they feel more comfortable with there being less risk, they may not opt for a c-section so soon (Wickham, 2015). Human factors are not considered in most research papers and yet they play a profound part in clinical care and emergency situations.
And there is more. A multi-centre, randomised, controlled trial was stopped early due to the increase in perinatal mortality and concluded people should be induced at 41-weeks gestation to reduce the risk (Wennerholm et al, 2019). This paper made headline news and caused many trusts to change their induction of labour guidelines. This was a knee-jerk reaction to one study that has significantly changed practice despite evidence to the contrary that found no difference in stillbirth rates or perinatal death when mothers were induced between 41-weeks- and-three-days and 41-weeks-and-five-days gestation, and 42-weeks gestation (Rydahl et al, 2019). By comparison, this evidence made no headlines.
A further study by Muglu et al (2019) has attempted to determine the chance of stillbirth at each gestational week from 37-weeks gestation. They reported the chance of stillbirth to be 0.11 per 1 000 at 37-weeks gestation, increasing to 3.18 per 1 000 at 42-weeks gestation (Muglu et al, 2019). While this is a statistically significant increase, it is still a small chance of an adverse outcome and therefore parents must be informed of both the absolute and relative risks of continuing a pregnancy beyond 41-weeks gestation.
One factor that must be taken into consideration for all these papers is that while there may be a small increase in absolute risk of stillbirth for those who opt for later induction of labour, every person is an individual and therefore their risk will be individualised. It follows that commencing a routine induction of labour protocol will not reduce this risk for all and therefore other factors should be taken into consideration when offering induction to mothers. These could include fetal movements, the mother's lifestyle and medical history, and other relevant factors.
Additionally, none of the papers have taken into consideration how mothers feel about induction of labour. One paper explores the evidence of people's experiences of induction. This found that parents did not feel involved in decision-making and felt that the decision was made for her and not with her (Coates et al, 2019). They felt that important information was withheld from them and that they were therefore unable to make an informed decision about whether they wished to be induced or not (Coates et al, 2019).
Furthermore, it was reported that the mother's feelings were not taken into consideration and they felt coerced into agreeing to induction of labour (Coates et al, 2019). Many mothers found the process rushed, more painful, lacked support and privacy with some reporting they felt they surrendered control to the healthcare practitioners and were not listened to (Coates et al, 2019). This contributes to dissatisfaction at such a momentous time in one's life and may contribute to feelings of regret agreeing to induction in the first instance as well as postnatal depression.
While there is clearly an argument for induction of labour, it should not become a commonplace routine paradigm, but an intervention offered based on individualised risk factors and open discussions with the mother. This should include providing the actual and relative risks of each option so parents can make a fully-informed decision about the path they wish to take.