Routine induction in healthy women not supported by evidence

Another study has shown that routine induction isn’t leading to a significant positive improvement in outcomes. 

The tiny improvement that can sometimes be seen in short term stillbirth rates “…may not outweigh the side effects or the costs.” (Haavaldsen et al 2022).

The latest study, based on Norwegian data, is merely the latest research to throw doubt on the wisdom of the rising induction rate in many countries. (You can find many other examples here).

The research was based on data from more than a million births. (1,127,945 to be precise.)

The researchers looked at data from the Medical Birth Registry of Norway.

They “…included all singleton births in gestational weeks 37–42 in Norway [and] calculated the prevalence of labor induction and outcome measures according to year of birth. We repeated these calculations for each gestational week at birth.” (Haavaldsen et al 2022).

More inductions for little benefit

The first thing the researchers found was that, in the years over which the data were collected (1999 to 2019):

“The prevalence of labor induction increased from 9.7% to 25.9%, and the increase was particularly high in gestational week 41.” (Haavaldsen et al 2022).

It’s worth noting that current induction of labour rates in several other high-income countries are significantly higher.

In some areas, induction rates are nearing 50 per cent, or half of all women.

As far as benefits were concerned:

“A modest decline in fetal deaths was observed in all gestational weeks, except gestational week 41. The overall decline was from 0.18% in 1999–2004 to 0.13% during 2015–2019. There were no overall changes in other perinatal outcomes.” (Haavaldsen et al 2022).

Let’s just pause and look at those numbers.

Yes, the fetal death rate went down a bit, but it went from 0.18% to 0.13%. So that is a difference but, as the researchers themselves emphasise, it’s very small. Hundreds of women would need to have their labours induced in order to prevent one stillbirth. 

But it’s not even as simple as that because, when we focus on stillbirth, we are only looking at the difference in short-term outcomes and ignoring deaths and illnesses and side effects that occur later.

Those are all higher after induction, which is why so many people are concerned.

We know from many studies that induction leads to more intervention and more problems than waiting in the medium and long term.

Which is a bigger concern than the tiny short-term difference.

I wrote about this in depth in In Your Own Time: how western medicine controls the start of labour and why this needs to stop.

Why stillbirth rates aren’t enough

I want to pause for a moment and explain the problem of focusing on short-term outcomes in a bit more depth.

The problem of focusing on stillbirth rates alone was explained really well in a recent letter to the British Journal of Obstetric and Gynaecology.

The letter’s authors were responding to a paper whose authors claimed that induction was making childbirth safer because of the slightly lower stillbirth rate found in some studies.

Here they explain why looking at stillbirth rates isn’t enough:

“It is logical that induction of labour will prevent some stillbirths from happening, because being born excludes dying in utero at a later stage. However, while reduction in stillbirth is a significant benefit, other studies have shown that this may come at the cost of higher rates of neonatal mortality, including sudden infant death syndrome.2 We previously showed that an induction of labour for non-medical reasons among low-risk women was associated with adverse health outcomes for both women and infants, compared with women with a spontaneous start of labour.3 Because a large number of women need to be induced to prevent one stillbirth, a more proactive practice style, as stated in the paper of Gural-Ulganci et al.,1 will come at the costs of other adverse outcomes in many women and infants.

Therefore, while information about stillbirth, neonatal unit admission and mechanical ventilation might be informative in decision-making, it is not sufficient. The information that is needed in practice includes a wider range of risks, beyond the immediate intrapartum period. This includes neonatal mortality (from birth until 28 days postpartum) and other short-term and long-term outcomes for women and infants.” (Seijmonsbergen-Schermers et al 2022).

What do women think?

The medium and long term effects of induction aren’t its only downside.

We know from several studies that many women are dissatisfied with induction and regret agreeing to this.

A pre-publication paper from the CHOICE study has confirmed that, “Women do not experience IOL as a benign and consequence free intervention.” (Harkness et al 2023).

The words of the women interviewed by Harkness et al (2023) make sad reading.

“Women often described poor experience of time spent in antenatal areas during CR [cervical ripening]: lack of privacy, lack of sleep, lack of food. They also reported a shortfall in support that midwives were able to provide before transfer to labour suite, manifested in lack of appropriate pain relief, lack of emotional support and concerns about clinical care.

“I was labouring behind a curtain, no privacy, others all around me… It was really hard to focus and stay calm and relax with no privacy of my own, no pain relief and no food.” {Participant 036, Multip, Hospital CR}

“I spent 3 days crying in pain unable to eat or sleep in hospital” {Participant 135, Primip, Hospital CR} (Harkness et al 2023).

Sadly, this is merely the most recent paper to show the same thing. More information here and here.

More interventions and problems

In Your Own Time was written to help parents and professionals better understand the issues and the evidence relating to the current induction epidemic. Looks at the evidence relating to due dates, ‘post-term’, older and larger women, suspected big babies, maternal race and more.


Back to the Norwegian research. This study also evidences the fact that induction leads to more interventions and problems:

“The prevalence of postpartum hemorrhage ≥500 ml increased from 11.4% in 1999 to 30.1% in 2019, and operative deliveries increased slightly. The prevalence of acute cesarean section increased from 6.5% to 9.3%, whereas vacuum and/or forceps assisted deliveries increased from 7.8% to 10.4%.” (Haavaldsen et al 2022).

It’s important to acknowledge that this is an association and not proof of causation. This study wasn’t designed to show any more than an association. There is, however, plenty of evidence from other research that induction leads to these sorts of problems.

And midwives, doctors and birth workers see it every day.

And the conclusion?

The authors conclude that:

“A high increase in labor inductions was accompanied by a modest decline in fetal deaths, but no decline in other adverse perinatal outcomes. In settings where the prevalence of adverse perinatal outcomes is low, the beneficial effect of increased use of labor induction may not outweigh the side effects or the costs.” (Haavaldsen et al 2022).

This is very clear, and it echoes the conclusions reached by growing numbers of people.

Routine induction isn’t beneficial, and any small increase in short-term outcomes is outweighed by medium and long-term risks. 

Earlier research

This is by no means the first study to show that routine induction isn’t evidence-based.

A 2018 systematic review looked at the effects of early induction of labour on the mother and baby and concluded that induction prior to post-term is associated with few beneficial outcomes and several adverse outcomes.

Sara Wickham’s bestselling book explains the process of induction of labour and shares information from research studies, debates and women’s, midwives’ and doctors’ experiences to help women and families become more informed and make the decision that is right for them.

The authors, Rydahl et al (2018), explain that the current shift towards earlier induction of labour which is occurring in many areas of the world “may lead to 15–20% more inductions. Given the fact that induction as an intervention can cause harm to both mother and child, it is essential to ensure that the benefits of the change in clinical practice outweigh the harms.” (Rydahl et al 2018).

The review, which focused on outcomes for healthy women, also showed cause for concern, but this and other reviews have been largely ignored by those writing obstetric guidelines.

Induction before post-term was found to be associated with an increased risk of caesarean section, chorioamnionitis, labour dystocia, precipitate labour and uterine rupture. There was a decreased risk of oligohydramnios and meconium stained amniotic fluid.

The authors concluded that, “Induction prior to post-term was associated with few beneficial outcomes and several adverse outcomes. This draws attention to possible iatrogenic effects affecting large numbers of low-risk women in contemporary maternity care. According to The World Health Organization, expected benefits from a medical intervention must outweigh potential harms. Hence, our results do not support the widespread use of routine induction prior to post-term (41+0–6 gestational weeks).” 

Their paper added to growing concerns about the effects of induction of labour on the health of women and babies.

These concerns keep coming.

You can find out more in my book, In Your Own Time: how western medicine controls the start of labour and why this needs to stop.

References

Haavaldsen, CMorken, N-HSaugstad, ODEskild, AIs the increasing prevalence of labor induction accompanied by changes in pregnancy outcomes? An observational study of all singleton births at gestational weeks 37–42 in Norway during 1999–2019Acta Obstet Gynecol Scand2022001– 16. doi:10.1111/aogs.14489

Harkness M, Yuill C, Cheyne H et al (2023). Experience of induction of labour: a cross-sectional postnatal survey of women at UK maternity units. Pre-print ahead of publication https://doi.org/10.1101/2022.11.30.22282928

Rydahl, E, Eriksen, L, Juhl, M (2018). Effects of induction of labor prior to post-term in low-risk pregnancies: a systematic review. JBI Database of Systematic Reviews and Implementation Reports doi: 10.11124/JBISRIR-2017-003587

Seijmonsbergen-Schermers A, Peters LL, Downe S, Dahlen H and de Jonge A. (2023). Induction of labour and emergency caesarean section in English maternity services: Examining outcomes is needed before recommending changes in practice. BJOG: Int J Obstet Gy. https://doi.org/10.1111/1471-0528.17359

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