Updated on: February 27, 2024
The ARRIVE trial (also known as the ARRIVE study) has created a lot of debate in the birth world since its release in 2018.
The study was conducted to determine how elective induction at 39 weeks of pregnancy impacts birth outcomes for the baby and Cesarean rates when compared to those who waited until 40 weeks and 5 days for elective induction.
Since the study was published, it has become common to hear that induction of labor at 39 weeks is best for mother and baby. The study suggests that it improves birth outcomes and reduces the likelihood of having a C-section.
However, parents planning a VBAC may have also heard that letting labor start and progress naturally can improve their chances of having a vaginal birth. This can be very confusing for parents, especially when trying to understand the ARRIVE trial and VBAC implications.
There are many things to consider when looking at the ARRIVE trial, especially when it comes to VBAC induction. This article will break down what the ARRIVE study is, its findings, who it applies to, what professional organizations say about it, and things you should consider if your provider is recommending induction at 39 weeks.
What is the ARRIVE study, and what does it say?
The ARRIVE study stands for A Randomized Trial of Induction Versus Expectant Management. The study contained over 6,000 first-time mothers birthing in 41 hospitals all over the United States.
Each mother was randomly assigned into one of two groups, either to be induced at 39 weeks or to wait in the expectant management group.
The participants in the expectant management group waited for labor to start on its own, could be induced for medical reasons, or could choose to be induced at 40 weeks and 5 days.
The goal of the ARRIVE study
The purpose of the ARRIVE trial was to see if inducing labor at 39 weeks improves birth outcomes and reduces the chances of having a C-section rather than waiting until 40 weeks and 5 days before inducing labor. They compared birth outcomes for mothers and babies between the two groups to determine if either had statistically better birth outcomes.
One of the outcomes the researchers were looking for was whether inducing at 39 weeks reduced the likelihood of having a Cesarean. It is important to note that when researchers expect a specific outcome, this bias may impact results and influence the behavior of the healthcare providers participating in the study.
ARRIVE trial Findings
Between the two groups, there were no significant differences in birth outcomes for the baby. However, the study did show that the mothers in the 39-week induction group had a lower chance of Cesarean (19% vs. 22%) and were less likely to develop high blood pressure (9% vs. 14%). The 39-week induction group had longer labors but shorter stays in the hospital postpartum.
It is important to note that a strict induction protocol was followed during the study for both groups. As of the date of this article, the only information that was released about the induction is that it included cervical ripeners (if the cervix was not favorable at the time of induction) and Pitocin. Without knowing the exact induction protocol, other providers cannot follow the same method to replicate the study’s findings.
Also not included in the findings are the consequences of a failed induction on birth outcomes.
I also find it interesting that the national Cesarean rate for first-time mothers is around 26% (31.7% as of article update), but this study had significantly fewer Cesareans than that. Without knowing the exact protocol used for either group, it is impossible to pinpoint why the Cesarean rates in this study were so much lower than the national average.
As of 2024, a few studies have looked at the effects of the ARRIVE Trial and concluded that the elective induction rate has significantly increased but the rate of Cesarean delivery was not significantly changed.
What do ACOG and the ACNM say about the ARRIVE trial?
Both ACOG (American College of Obstetrics and Gynecology) and the ACNM (American College of Nurse-Midwives) agree that the findings of this study are not solid enough to start recommending routine elective induction.
We are concerned that these study results have a high potential to be applied in ways that are not consistent with the parameters of the ARRIVE trial, which can result in unintended consequences.
The American College of Nurse-Midwives
ACOG notes that it is reasonable that an elective induction may be offered at 39-weeks but discourages against implementing policies that make this a standard of care. They also emphasize shared decision-making between the care provider and the birthing person.
VBAC + the ARRIVE trial, how does it apply?
Here is the thing about VBAC and the ARRIVE trial; the results don’t apply to women planning a TOLAC. There are two reasons for this.
First, the study participants only included first-time parents. Because most people who have had a Cesarean have labored to some degree, the results are not applicable. We know that second births typically are faster and shorter when the cervix has previously experienced labor (not always, but usually).
Second, the induction protocol of the ARRIVE study included the use of artificial cervical ripeners, which is contraindicated for VBAC. Using artificial cervical ripeners significantly increases the risk for uterine rupture. Therefore, it would be impossible to follow the same induction protocol used in the study, even if it was made known.
Other ways to reduce your chance of having a Cesarean
You can address many factors besides induction date that have a more significant impact on reducing your chances of having a Cesarean.
Midwifery-led care, both in-hospital and for home birth (HBAC), has drastically lower Cesarean rates than OBGYN care, without the regular use of induction. Consider having a midwife attend your delivery. Having a VBAC-friendly provider who is comfortable with the natural birth process will significantly impact your chances of avoiding a Cesarean.
Other things that reduce your chances of Cesarean and other interventions during childbirth include:
- Remaining mobile as much as you can, and avoiding an epidural as long as possible
- Choosing a supportive provider and a birth location with a high VBAC rate
- Laboring and giving birth in water, whether at home or in a hospital (where permitted)
In addition, studies show:
- Having doula support decreases your chance of having a Cesarean by 39%
- Intermittent monitoring vs. continuous fetal monitoring reduced the likelihood of having a Cesarean by 25%
Other than a 39-week induction, there are so many options that will help parents avoid a Cesarean, whether first-time mom, fifth-time mom, or VBAC.
What should I do if my doctor wants to induce me at 39 weeks?
This is where having a supportive provider who understands your birth goals and will work with you to achieve them is crucial. While there are a few medical reasons for labor induction, you might find you want to wait for labor to start on its own when you and your baby are healthy.
If your doctor or midwife recommends an elective induction at 39 weeks, it is crucial to understand why they recommend this option. I encourage you to have an open discussion about your options, including the risks and benefits of each, and make a decision only when you are 100% comfortable.
It is ok to ask for more time. It is ok to choose elective induction. The most important thing is that you are the one making the ultimate decision surrounding your care and that your decision is made with confidence and not coming from fear.
FAQ
What percentage of first-time moms get induced?
For first-time moms, the average length of gestation is 41 weeks and one day. For second-time moms, it is 40 weeks and three days. However, ACOG estimates that 20-40 percent of parents will be induced before they hit that point in pregnancy.
Is it bad to get induced at 39 weeks?
Labor induction at 39 weeks pregnant is not bad. However, elective induction should be avoided if the mother and baby are healthy. There are no clearly established benefits of induction at 39 weeks compared to waiting for spontaneous labor. However, every pregnancy is unique and should be treated as such. Make your decision with a healthcare provider that understands your individual needs.
Should I have an elective induction?
Elective induction before 39 weeks of pregnancy should be avoided unless it is for the safety of the mother and baby. After 39 weeks, elective induction poses fewer risks and is generally considered safe. Some parents prefer to wait for their bodies to progress and labor naturally, without intervention. Either option is reasonable and should be carefully considered.
What is the Arrive trial?
The ARRIVE trial is a controlled study of over 6,000 participants conducted to determine if elective induction at 39 weeks of pregnancy resulted in better birth outcomes for mother and baby when compared to waiting for spontaneous labor (expectant management).
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Updated Sources:
Nethery, Elizabeth PhD, MSC; Levy, Barbara MD; McLean, Kate MD, MPH; Sitcov, Kristin BS; Souter, Vivienne L. MD. Effects of the ARRIVE (A Randomized Trial of Induction Versus Expectant Management) Trial on Elective Induction and Obstetric Outcomes in Term Nulliparous Patients. Obstetrics & Gynecology 142(2):p 242-250, August 2023. | DOI: 10.1097/AOG.0000000000005217
Wood R, Freret T, Clapp M, Little S. Changes in induction of labor and cesarean delivery post ARRIVE trial: a quasi-experimental analysis. American Journal of Obstetrics & Gynecology. 2023 Jan. | DOI: https://doi.org/10.1016/j.ajog.2022.11.019
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