Last week I was asked to speak to doulas from the Doula Training Academy about the complexities of the ARRIVE study so I thought I would write a blog based on that webinar.
The doulas wanted to better understand the conclusions of the ARRIVE study as there is other evidence that induction of labour increases the risk of caesarean section.
They also wanted to know how to respond to their clients’ questions if they had a care provider using the ARRIVE study to justify offering an induction at 39 weeks.
There are some great blogs on this topic already and I drew inspiration from some of them for the webinar.
(NB I am going to call it the “ARRIVE study” or “the trial” because ARRIVE stands for “A Randomized TRial of Induction Versus Expectant Management” so it is actually a tautology to call it the ARRIVE Trial 😬)
The ARRIVE study for Doulas
“Conclusion: Induction of labor at 39 weeks in low-risk nulliparous women did not result in a significantly lower frequency of a composite adverse perinatal outcome, but it did result in a significantly lower frequency of cesarean delivery” (Grobman et al. 2018).
However, it is important to look into this statement further.
As with any study, it is important to read beyond the abstract to really understand if this evidence applies to your client, let alone if it should change obstetric practice or not.
Firstly it is important to know why the researchers did the study.
The researchers’ primary goal was to see if elective induction of labour (IOL) at 39 weeks of low-risk first-time mums reduces the risk of “a composite of perinatal mortality and severe neonatal morbidity” when compared with expectant management (EM) of low-risk first-time mums.
The secondary outcome was to see what effect this had on caesarean sections.
So what were these “composite adverse perinatal outcomes”?
- Perinatal death
- Resp. support with 72 hrs of birth
- APGAR </= 3 at 5 min
- Hypoxia =ischemic encephalopathy
- MAS (meconium aspiration syndrome)
- Birth trauma
- Intracranial or subgaleal haemorrhage
- Hypotension requiring vasopressor support
(Grobman et al. 2018)
While it is great that IOL at 39 weeks did not increase these risks, it didn’t significantly lower them either. Which leaves me wondering what was the frequency of these severe outcomes before the trial? Has anything else been done to address these risks? And how does this level of risk compare with the research into outcomes with different models of care?
In the study, 94% of the women were in the care of an OB and 6% were with midwives. Would the results have been different if more women were in a midwifery-led model of care?
A 2016 Cochrane Review into the outcomes for different models of maternity care found that:
Authors’ conclusions: This review suggests that women who received midwife-led continuity models of care were less likely to experience intervention and more likely to be satisfied with their care with at least comparable adverse outcomes for women or their infants than women who received other models of care.Further research is needed to explore findings of fewer preterm births and fewer fetal deaths less than 24 weeks, and all fetal loss/neonatal death associated with midwife-led continuity models of care. (Sandall et al. 2016)
It is also important to know what the actual caesarean section rates were in the study.
They were 18.6% in the IOL group and 22.2% in the EM group.
So whilst there is a statistically significant difference, the difference actually isn’t that much and both rates are too high for low-risk women.
Another question that it is important to ask with any research is what was the sample size and is the sample representative?
The researchers of the ARRIVE study initially wanted 50,581 women in the study.
During the process, they ended up with 22,533 women who were considered eligible for the study (remember they had to be completely low risk throughout their pregnancy).
Of the 22,533 they tried to recruit to the study only 6,106 agreed to be in the study.
This meant they ended up with a very specific sample of women who were happy to be randomly controlled into either group and potentially have an induction for no medical reason. Does this sound like your client?
They also ended up with a much smaller sample size than they originally deem important for the study.
Also, there was no specific induction protocol mandated for women who underwent induction in either group.
There are quite a few variations on how different care providers like to induce their clients so this really makes it hard to know if the results apply to how your client’s OB is planning to induce her.
(Another big issue with the ARRIVE study is that we have to balance the results with what happens in the real world. I have written a previous blog on this)
The trial also only looked at low-risk first-time mums. So if your client is not in this category then the OB should not be mentioning the trial at all.
The results may also not apply to your client simply because she has you as her support as nowhere in the study does it mention doulas.
Something else that is important to know about the ARRIVE study is that it wasn’t comparing IOL with spontaneous labour.
It compared IOL with “Expectant Management”.
The women in the EM group had to agree to “forego elective delivery before 40+5”, but they could be induced after this date.
When you look at the range of when women had their babies in both groups you realise that some women in the EM group must have been induced. (Mittendorf et al. (1990) found that the median gestation length of first-time mums was 41+1).
Is the study really just comparing early IOL with later IOL? Or is it not even comparing that? Is it actually comparing different methods of induction which haven’t been clearly accounted for in the study? (In research terms, they didn’t control for this variable)
The intended parameters for the groups were defined as IOL to birth at 39 to 39+4 weeks and EM to birth at not before 40+5 and not after 42+2.
But what actually happened was the IOL group all had their babies between 39+1 and 39+6 and the EM group had their babies between 39+3 and 41 weeks.
As you can see from the graph that is quite some overlap. Was it the women in the overlap that ended up with caesarean sections in both groups? Were they induced if in the EM group and if so how?
(If you are interested in the reasons for non-compliance with the original study parameters you can read them HERE. They do raise a whole lot of other questions 🤔)
The researchers actually addressed this issue themselves in the paper
“These findings contradict the conclusions of multiple observational studies that have suggested that labor induction is associated with an increased risk of adverse maternal and perinatal outcomes.4-6 These studies, however, compared women who underwent labor induction with those who had spontaneous labor, which is not a comparison that is useful to guide clinical decision making. Conversely, our findings are consistent with observational studies,7-11,20-23 as well as the randomized trial conducted by Walker et al.,12 in which women undergoing labor induction were compared with women undergoing the actual clinical alternative of expectant management” (Grobman et al. 2018)
I am really not sure why they think comparing IOL with spontaneous labour is not useful to guide clinical decision-making.
Are they saying that when you compare induction with spontaneous labour, induction does increase risks to babies and mothers but when you compare induction with expectant management (which probably ends up in an induction) they don’t, but this doesn’t matter to us?
Another interpretation is that doing nothing actually lowers the risk to babies and mothers when compared with clinical management.
Alternative interpretations of the ARRIVE study
There are a couple of well-respected authors who have proposed these alternative interpretations of the ARRIVE study:
“Routine IOL at 39 weeks confers a minor reduction in c/section rates (<3 per 100) and no advantages to babies” – Henci Goer
“Awaiting spontaneous labour after 39 weeks in the care of an obstetrician increases your risk of caesarean section” – Dr Sara Wickham
But let’s ignore the other research that shows induction increases the risk of caesarean section in first-time mums. Let’s assume that the results of the ARRIVE study are valid and look at a way to help your clients discuss the ARRIVE study with an OB who suggests an early induction to lower the risk of caesarean.
As with everything it comes back to encouraging them to use their B.R.A.I.N technique for informed decision making.
Here is how I would frame the B.R.A.I.N. questions
1.”So you have told me one benefit of an induction at 39 weeks, what are the risks of an induction?”
As we know inductions are not without risk and does this one benefit outweigh the risks?
(NB. I would also be asking if this approach is working for the OB. Your client could also ask “Of the low-risk women you induce at 39 weeks how many end up with a c/section?”. That is a really important statistic to know.)
Here are some risks of induction:
- The study showed that women who were in the IOL group had longer labours than the EM group ( 20 hrs vs 14 hrs)
- Inductions can lead to breastfeeding difficulties (Dr. Sarah Buckley is currently doing the research into this)
- Inductions have been found to increase the risk of PND
- You can read the common side effects and risks of syntocinon HERE
Another risk is prematurity of the baby.
Not all babies are “ready” at 39 weeks and this can lead to short and longer-term issues. A study by Dahlen et al. 2021 looked at this and there is an Australian public health initiative that no baby should be born before 39 completed weeks without a clear medical reason. (You can read more about this in a previous blog HERE )
Just because we can state one benefit for something does that mean we can dismiss all the risks? For example, formula-fed babies are less likely to get jaundice, so should we recommend formula over breastfeeding?
During the webinar, one of the doulas mentioned another benefit that an OB had told her about. This was that the ARRIVE study showed women in the IOL group felt a greater sense of control.
This is a great example of needing to know the numbers when someone makes (cherry-picks) statements like this.
Yes the study did find this, and that women in the IOL group reported lower pain levels, but they also said:
“Although differences in scores were statistically significant, they were relatively small” (Grobman et al. 2018).
And if you want to know the numbers:
For perceived sense of control during childbirth (as measured by the Labor Agentry Scale) at 6 to 96hrs after birth, the IOL group median was 168 points and the EM group median was 164 points, and at 4 to 8 weeks after birth the IOL group median was 176 points and the EM group median was 174 points (Grobman et al. 2018).
For a pain scale of 1 – 10, the median worst pain score for the IOL group was 8 and for the EM group was 9. The overall median pain score was 7 for both groups (Grobman et al. 2018).
So really not a great difference in either. And actually quite high in both.
Even if women did feel a greater sense of control and less pain in the IOL group I would argue there are far less invasive, and potentially harmful, ways of helping women feel a sense of control and lowering their experience of pain during their labour and births.#Doula #childbirtheducation
2. “Are there any other evidence-based ways of lowering my chance of a c/section?” (alternatives)
As a doula reading this blog I am sure you are well aware of the research that doulas lower the rate of caesareans. Is the OB who is offering an induction to lower the risk of caesarean also offering a doula? Is your client’s OB embracing you with open arms?
Are they also offering your client midwifery-led care? Midwifery-led care has been shown to lower caesarean sections
Is the OB also telling your client to attend good quality independent childbirth education classes rather than the hospital classes? Independent evidence-based childbirth education has been shown to lower c/section rates?
They probably are not going to be forthcoming with the above ways of lowing the chances of caesareans but are they at least going to follow the ACOG guidelines for the safe prevention of caesarean section?
3. “What is going to happen if I decline the induction and do nothing?”
Your client could ask: “so if I agree to the induction at 39 weeks can you guarantee I won’t end up needing a caesarean?”
But it is also important to remember that the ARRIVE trial compared induction of labour with expectant management, not doing nothing. So if your client declined induction at 39 weeks they might also like to decline being “managed” at the end of their pregnancy too.
Often when women decline induction hospital and OB policies suggest more monitoring, which can be stressful. They can also be of limited benefit and possibly be of harm.
4. And remember to check in with their instincts.
How comfortable is your client with doing nothing and letting nature take her course?
Often at the end of pregnancy couples can become impatient to meet their babies and the offer of an induction can be very appealing.
I think you as their doula can have a big role to play in helping couples understand the benefits of waiting.
I truly believe that the end of pregnancy teaches us patience which is something we need in abundance as new parents. We also need to learn to slow down before our baby is born. Babies’ brain waves are much slower than ours and we need to learn to give them time to coordinate their newborn reflexes, particularly when it comes to their breastfeeding.
I highly recommend Dr. Sara Wickham’s book “In Your Own Time” to help your clients realise the profound benefits of waiting for both baby and mum.
Pip Wynn Owen is an Award -Winning Childbirth and Early Parenting Educator, Registered Midwife, and Mother of 4. Pip prides herself on keeping up to date with the latest research and information so that she can help parents get the birthing experience they deserve by increasing their confidence and knowledge and promoting an equal partnership with their maternity care providers. Pip also believes in educating and empowering midwives of the future and as such is a Guest University Lecturer and Speaker at study days and conferences. Through her passion for improving birth experiences for couples, Pip has become a sort-after commentator on maternity issues and makes regular appearances on National Radio and TV. She has also been asked to write opinion pieces for national newspapers. She is also a regular contributor to magazines and online blogs.
Find out more about Pips classes and workshops HERE