EBB 393 - Evidence on Inducing at 41 Weeks or Later

Hi everyone, on today's podcast, we're going to talk about the evidence on inducing labor at 41 weeks or later. Welcome to the Evidence-Based Birth Podcast. My name is Rebecca Decker and I'm a nurse with my PhD and the founder of Evidence-Based Birth. Join me each week as we work together to get evidence-based information into the hands of families and professionals around the world. As a reminder, this information is not medical advice. See ebebirth.com slash disclaimer for more details. Hi everyone, today I am so excited to bring you today's podcast all about the evidence on induction of labor at 41 weeks or later. So today along with my co-host Dr. Sara Ailshire, we have a lot of brand new evidence-based information to bring to you. So Sara is a member of the EVB research team and she has come onto the podcast many times to share her research updates. And today Dr. Sara is here to talk about our latest signature article all about the research on inductions at late term and further beyond in pregnancy. So this episode is a companion podcast episode to our earlier podcast on the evidence, what is a due date? Episode 384 which came out in January of 2026. So Sara welcome back to being a co-host on the podcast with me. Hi, thank you so much for having me back on. It's always good to be back and get on the pod and talk about what we've been up to. So I'm really excited to talk about everything that we've added to this article, the latest research on the topic and to finish up our two part series about due dates and induction at 41 weeks and beyond. So we've been working on these for a really long time and now that we're recording this podcast it means that we're at the finish line. It's always a great feeling when these big projects come to an end and we get to share what we've learned with everybody. Yes, and now all this work that we've put into the many hours you've put in, I've been helping edit, we get to the point where we can share it with everyone and we love being able to share the evidence with you. So if you want any of the materials or scientific references that go along with this episode, it's super simple to access. Just go to evbirth.com slash inducing due dates and everything there is waiting for you. So just to rewind a little bit, I originally published the evidence on due dates here at Evidence Space Birth in the year 2015 and then we updated that article in 2020 and we now have a lot of new content here at Evidence Space Birth about due dates and induction. I want to point out that in the past we call this signature article the evidence on inducing for due dates, but we're changing the title of this article to the evidence on inducing for 41 weeks or later. And that's because after the 39 week time point, which we cover in a separate podcast and article all about the arrive trial, 41 weeks or one week past your due date is the next time point that researchers focus on. There is surprisingly very little research about being induced for your actual due date of 40 weeks, but there's been a ton of research recently on being induced at 41 weeks. And so that's why we're focusing on 41 weeks in the signature article and on this podcast. As a content note, in this episode, we will discuss the risk of stillbirth, which is the loss of a baby at or beyond 20 weeks of pregnancy. We also talk about the risk of newborn death. Stillbirth and newborn loss touches the lives of many parents, birth workers and providers all around the world. And in the show notes, we will share some resources that honor the babies lost and support parents and families affected by this type of loss. Now last time on the podcast when Dr. Sara was here, we talked about the science behind due dates. So we could understand where that 40 week number comes from, what that estimate gets right and gets wrong. We also talked a little bit about why providers may get concerned when a pregnancy goes past term or past the due date. In this episode, we're specifically focusing on 41 weeks, which is one week past the due date. And we're going to also focus on why providers might recommend or at least start talking about inducing at 41 weeks once you've gone past your due date. So if you're pregnant or you're hoping to become pregnant and you want to learn more about what to expect, if you go past your due date, or if you're a birth worker, maybe a doula, childbirth educator, your clients have questions about induction at the end of pregnancy, especially if they really wanted to go into labor on their own. Hopefully today we can help you out. We want to cover why someone might start hearing from providers that they need to be induced after they go past their due date. The difference between a medically indicated induction and an elective induction. We're going to talk a lot about what the research says, what the health outcomes are when labor is induced at 41 weeks instead of waiting for labor to begin on its own, which is also called expectant management. We are going to summarize the benefits and the risks of induction at 41 weeks and beyond. And we're going to talk about what the professional guidelines say on this topic. We're going to answer some frequently asked questions about these topics. And of course we'll end by giving you the bottom line. So Sara, can you start us off by explaining how common is it for someone to be induced for going past their estimated due date? Yeah, that's a great question. That's where we start in the article. In 2022, which is some of the most recent data that we have, the total induction rate in the United States was 31.8%. And this comes from a review of American birth certificate data that was published in 2024. But that number might be inaccurate because research suggests that induction of labor is probably underreported in the federal vital statistics that we get so much of our information about pregnancy, childbirth, and birth outcomes from. Also specific details about induction are not recorded in standard US birth certificate data. So we cannot know for sure how often people may have different types of inductions or why inductions are carried out, for example. However, there are researchers who are trying to help answer this question. We do know, for example, that 40% of participants in the Listening to Mothers in California survey that was published in 2018 reported that their care provider tried to induce their labor. The researchers then were able to ask the participants in the study for the reasons why they were induced. And two of the most common reasons for induction were, one, out of everybody who was induced, 35% of those said that they were induced because their baby was full term and close to the due date. And then another 22% of those who said that they were induced said that they were induced because their healthcare provider was concerned that they were overdue. So induction can be a really helpful tool if there's something that's happening in pregnancy that can put the parent or the baby at risk. I have told my story on the podcast before. I was induced for pre-clampsia, for example, and I'm really grateful that I got the care I needed to have a healthy birth and be doing well today. And there are some people who choose induction for themselves at term. They think it's the best option for them. They're ready. It's their free choice. However, in the research from Listening to Mothers in California data that we have, we see that some providers consider being overdue or being past your due date a medical reason for why somebody might need an induction. Yeah. While you were talking, it's reminding me of how frustrated you and I were at trying to find information on how often labor is induced for going past the due date because it seems like it's something that we don't really have documented anywhere, at least on a national basis. And I know we were able to look at a few countries, but worldwide it just seems like we're just guessing how often induction happens for going past your due date. We get a lot of comments from doulas in particular who say almost all of my patients are getting pressure to be induced at 39, 40, or 41 weeks. And I'm just affirming that this was a difficult subject to find data on. Yeah, absolutely. We can find information about induction, even if that information, which other researchers have documented, might be a little bit imperfect. If we had our wish list of all the data that we could have, it'd be really nice to have a little bit more insight into this and be able to really understand you, do people's experiences, like birth professionals' experiences, does that align with what the numbers are? But we don't have them. So Rebecca, would you mind walking us through the distinction between a medically indicated induction and an elective induction when it comes to going past your due date? Yeah. I know you mentioned having a medically indicated induction a few minutes ago. So in general, inductions are considered to be medically indicated when there are medical problems or pregnancy complications present that make it less safe to continue the pregnancy. Medically indicated inductions typically refer to inductions where the motivation for attempting to induce labor is either to respond to a medical condition that could threaten your health or the well-being of your baby, or a situation where giving birth could help resolve a medical condition before it becomes worse, such as with preeclampsia. So medically indicated inductions can happen anytime during pregnancy. They can happen well before your due date if there's a medical indication. It can even happen before viability or the age where fetus can be born and have a chance of surviving outside the womb. So we do have a reference list and you can access that for descriptions of medical conditions in which preterm or early term birth via induction and or caesarean may be recommended by providers. So we can have medical complications that may be called for an induction all the way to like we need this induction to save your life and everything in between. Now labor inductions that do not have a clear medical reason or indication for taking place are called elective inductions. So elective inductions might occur for preference reasons or for social reasons. If you or your health care provider want the birth to happen when a specific provider is on duty, for example, or maybe you need to schedule the birth around the availability of a partner or a support person. Maybe they're about to be deployed and you want to have the baby before they leave. Inductions that are elective might also occur for reasons like wanting to be done with an uncomfortable pregnancy or maybe you live a long distance from the hospital. So you feel like it's safer to induce rather than risk going into labor and having the baby in the car on the way there. Or maybe there's an upcoming blizzard or hurricane or you're trying to plan care around other children or dependents. So there are a lot of reasons why someone might choose an elective induction. Now opinions can differ on what is the best most inclusive term to use when we're referring to inductions that don't have a clear medical indication, including when inductions are done for reaching your due date. So there is controversy over what would we call an induction simply for reaching 41 weeks, for example. So in the signature article, we chose to use the term elective induction when we're talking about situations like that that don't have a clear medical indication because it's the term most commonly used in research. And we're writing about this topic for a general audience. And we also try to use the terms that researchers use to ensure we're accurately representing their work. So in the United States, elective inductions typically do not occur earlier than 39 weeks in zero days. And this is sometimes referred to as the 39 week rule. And that's because in 2009, there was a set of guidelines published by the American College Obstetricians and Gynecologists, known as ACOG, and the Society for Maternal Phenomenosin, where they advised against elective inductions prior to 39 weeks of pregnancy due to the known increased risk of complications for infants who are born in that early term period between 37 weeks, zero days and 38 weeks, six days. But sometimes the lines between an elective versus a medically indicated induction are blurred and not always clear. So some providers consider being induced for late term pregnancy, which is considered 41 weeks, zero days to 41 weeks, six days, or postterm pregnancy, which is considered to be 42 weeks, zero days and later to be medically indicated because of the increased risk of complications that come with longer pregnancies. While others might refer to it as an elective induction, if there are no existing health problems at that time. And as I mentioned earlier, to stay consistent, and because this is what the term most of the researchers use, we will call those inductions at 41 and 42 weeks when there's no other health problems, we'll call those elective inductions. Now, when someone gets closer or past their due date, they might start facing that question, should we induce labor or should we wait for labor to start on its own? Or maybe you don't want to wait forever, but you're willing to wait just a few more days or maybe one more week. Another way of referring to waiting for labor to start on its own, usually with fetal monitoring to monitor the baby's status is called expectant management. And expectant management can sometimes result in spontaneous labor where you went into labor on your own, and it can sometimes result in choosing an elective induction later or having a medically indicated induction later. That is often compared in the research with a more active management style where labor is induced electively for getting close to reaching or passing the due date without any other health problems indicating a need for induction. So there is a lot of research comparing the benefits and risks of this more active management style using an elective induction at certain time points versus expectant management. And that research kind of spans the length of time from 39 weeks to 42 weeks and beyond. So Sara, I think now let's turn to that research. You know, what does the research say about outcomes when labor is induced primarily at 41 weeks? Cause that's what we're going to focus on today in this podcast instead of waiting for labor to begin on its own. Absolutely. So before we get into that, though, I wanted to talk a little bit about some of the limits of the research evidence that we have that compares induction at 41 or 42 weeks with waiting for labor to start on its own. And just as a disclaimer, research is not a perfect process. And the fact that we can talk about some of these issues from previous research studies means that researchers know about this and can account for this in future studies as a design new randomized controlled trials or as a study, you know, existing medical records doing user observational research. So we have identified four of these things that keep in mind. First, many of the clinical trials on induction versus expectant management were carried out in countries or during time periods with comparatively lower cesarean rates than you might find in another country or today, depending where you are in the world. These research findings on cesarean rates and inductions might not apply, you know, to people who are giving birth in hospitals that have high cesarean rates. You know, the setting of birth would matter a lot. And if you're giving birth in a hospital that puts a really strict time limit on the length of labor that discourages mobility and position changing. Or, you know, if you have epidural doesn't provide assistance with, you know, moving you around as you might need. You might have a very different experience with an induction than somebody who's induced in a hospital where birth and people have freedom of movement. They're able to rest. There's greater shared decision making. We hope that research is sort of like generally applicable. That's the goal. But circumstances can matter and can maybe impact how applicable, you know, a study might be to your circumstances. Another limitation is that the correct comparison group for elective induction includes people who are induced later in pregnancy, as well as those who go into labor spontaneously. Most researchers, though, only report the results of the two study groups as they originally are defined or as people are originally assigned. Those who are meant to have the management or the induction versus those who are meant to have expected management. But it can be more helpful to look at the results for people who are actually induced or who actually went into spontaneous labor. For example, in the signature article, we spend some time talking about an older study from the 1990s, the Hanna postterm trial, which is a very important research study, even though I think it's like over 30 years old at this point, even say it remains one of the biggest studies about induction for reaching 42 weeks in this trial, about one third of mothers who were assigned to the induction group went into labor spontaneously before the induction. So when you look at the breakdown of what actually happened to the people in the two research groups, as we do in the article, it becomes apparent that the Caesarean rates only increased with the expected management when induction occurred in the pregnancy later and not when mothers went into spontaneous labor later in the pregnancy. The third thing to consider is that in most studies, people in the expected management group have more fetal testing while they're waiting for labor to begin. And some of these tests might have shown possible signs of distress and some of those results could have been false positives. So extra fetal testing could possibly lead to higher rates of Caesarean for a suspected fetal distress during labor in an expected management group. And the last point to consider is that induction protocols can vary from study to study. And sometimes they can even vary within the studies themselves. So this was another issue in the Hanna postterm study. People in the active management group first received drugs to ripen their cervix and then got drugs to induce labor while the people in the expected management group who ended up with an induction did not have cervical ripening. So it's known that if you have an induction about cervical ripening, you are more likely to have a Caesarean as an outcome. So in this case, the expected management group would have been an increased risk of Caesarean compared to the active management group. Yeah. So you mentioned the Hanna postterm trial that came out in the 1990s that had a really big impact. I think people used to think you just let people go on as long, you know, they'll go into labor when they go into labor and you shouldn't really induce them. And then after the Hanna postterm trial, the 42 week point kind of became the point that everybody was like, all right, this is where it's safer to be induced. And there are some limitations, as you mentioned, to the Hanna postterm trial. And you can learn more about it in the signature article. But then what happened next was in the late 2010s, there were two big trials that came out of Northern Europe on the 41 week time point. There was index that was published out of the Netherlands and Sweepis from Sweden. So, Sara, should we start with kind of breaking down the index trial? Yeah, absolutely. So the index trial is named for the acronym that the researchers used to stand in for the full title of their study, which was induction at 41 weeks, expected management at till 42 weeks. So IND EX. This was a multi-center trial that was connected at 123 midwifery practices and 45 hospitals in the Netherlands, where midwives are lead professionals for most pregnancies and births. The researchers randomly assigned a total of 1,801 pregnant people to either being induced at 41 weeks in zero to one days, or to expected management and then an induction if needed at 42 weeks in zero days if labor had not started on its own by that point. In the Netherlands, at least at the time of the study, labor is not usually induced before 42 weeks with an uncomplicated pregnancy. So they were able to get the ethical approvals they needed to conduct a study. In the US, for example, it is not standard practice in many practices to continue expected management for as long as 42 weeks. So it might have been more difficult to get the same ethical approvals needed to do that study here, for example. Prior to people were enrolled into the study between 2012 and 2016. The mothers had to be healthy and pregnant with single head down babies. Everybody had to have a gestational age that was estimated with ultrasound before 16 weeks of pregnancy to ensure that they had the most accurate estimate of how far along they were in their pregnancy. They excluded anybody from the trial who had a previous caesarean, who had a high blood pressure disorder, who had expected or known problems with the baby's growth, whose baby had an abnormal fetal heart rate, or where there were known fetal malformations or other known complications of the pregnancy. In both of the research groups, cervical ripening and induction methods depended on local protocols. So thinking back to some of the issues we talked about in research, this is one that continued. It's an important weakness in the index study because, again, like that big Hannah postterm trial, individual providers in the index trial might have managed labor inductions differently depending on group assignment. The variation in induction methods used in the study also limits the study's generalizability or the ability to apply the results to the population at large. Since care providers lack an induction protocol that they could replicate, that they could kind of follow, so hopefully see the same results. In the elective induction group, 29% of the participants had spontaneous labor before their induction and 71% were induced. In the expected management group, 74% of the participants had spontaneous labor before their planned induction and 26% were induced. Interestingly, the median decrease in length of pregnancy between the two groups was only two days. So in other words, the median pregnancy was only two days shorter in the elective induction group compared to the expected management group. I always find that fascinating when they're like, this group is going to be induced and then this group is going to have expected management and it's supposed to be a week's difference, but it's just really two days. So we're looking at the difference of average pregnancy length of like, what does it do when you make a pregnancy two days shorter at this time point? So what did they find? Yeah. So for the mothers, the findings were that there was no difference in cesarean rates across the two groups. It was about 11% of birth and people in each group had a cesarean. There was also no difference in combined measure of bad outcomes for mothers. It was about 11 to 14% in both groups. This outcome was called by the researchers, the maternal composite adverse outcome rate. And what they did was a grouped a bunch of negative outcomes you would hope not to see together. You know, I mean, they also looked at those outcomes individually, but they put them in a group together just to see sort of generally what were these undesirable outcomes that happened in total. And these included excessive bleeding after birth or requiring a manual removal to placenta, severe tears or admission to the intensive care unit or, you know, maternal death. There were no maternal deaths that occurred in either group in the study. And the researchers did not report on the rate of uterine rupture in either group. The other major outcome they looked at were, how were things for the babies? So babies in the elective induction group had a lower composite adverse outcome rate of 1.7% in the induction group versus 3.1% in the expected management group. And this combined negative outcomes, same thing is same sort of name as for the mothers, but included different negative outcomes. And these were perinatal death, an apgar score of less than seven at five minutes, a measure of umbilical blood that identifies that there's a problem of low oxygen, meconium aspiration syndrome, nerve injury, brain bleeds, or admission to newborn intensive care unit or NICU. It was mostly the lower rate of apgar score of less than seven at five minutes that contributed to the lower combined adverse outcome with the elective induction group 1.2% with the elective induction versus 2.6% with expected management. The researchers noted though that there were no difference in rates of apgar score of less than four at five minutes. However, the combined outcome was still significantly lower in the elective induction group if using apgar score of less than four at five minutes and excluding fetal malformations. There was one stillbirth that occurred in the elective induction group at 40 weeks and six days before the mother was induced. And there were two stillbirths that occurred in the expected management group while the mothers were waiting for labor. One stillbirth was to a first time mother. I had occurred at 41 weeks and three days and her baby was small for gestational age. The other stillbirth occurred to a woman who had had previous births. It took place at 41 weeks and four days and her placenta showed signs of infections. There were no newborn deaths in either group. And I should note that this concern about a small for gestational age infant is something that we talked about in the previous podcasts and we cover a little bit more in depth in the companion signature article on what is a due date. But just for our audience who might not have seen those or might not have listened to the last podcast, when a baby is small for gestational age, meaning that they're estimated to be at or below the 10th percentile for weight, it doesn't necessarily mean that something is wrong because sometimes people are small and they have small babies. However, sometimes a baby being very, very small can mean that there's something that has gone wrong, either due to an underlying genetic condition or another problem in pregnancy, maybe with the placenta or the umbilical cord that has negatively impacted their growth and could have potentially contributed to their death and utero. And finally, for this, for the group of babies in the study, there was no protocol for fetal monitoring. It like the protocol for induction and varied from place to place. But in general, fetal monitoring and assessment of amniotic fluid levels was typically performed between 41 and 42 weeks for research participants. So in summary, the index trial found that elective induction at 41 weeks resulted in similar cesarean rates and fewer overall bad outcomes for babies compared to waiting for labor until 42 weeks. The absolute risk of a bad outcome, a combined measure of pernatal death, intensive care and mission or APGAR score of less than four at five minutes, was low in both groups. 1.7% in the induction group versus 3.1% in the expected management group. So has there been any more research about this that's come out since index? Yeah. So something else that was interesting was that three years after the index study was published, the researchers also published a companion study in 2022. This companion study was inspired by the fact that not everyone who was asked to participate in the index trial agreed to take part. In fact, about 69% of those who were invited to participate in the trial declined because they did not want to be randomly assigned to one group or the other. So in this companion study, researchers followed the labor and birth outcomes of those who declined to participate in the index trial in order to see if characteristics and health outcomes differed between those who were in the trial versus those who declined to participate. So they looked at people who gave birth at 90 midwifery practices and 12 hospitals in the Netherlands between 2012 and 2016. And they were able to recruit 3,642 women who met the same requirements as those who were enrolled in the index study. And for the purposes of analysis, the participants were grouped into three categories according to their preferences for either one induction, two, expected management, or three, if the researchers couldn't identify a preference and they called them the unknown preference group. So I guess in the study, which was observational, sorry, they're just trying to observe the outcomes when people fall into one of these groups naturally, either induction at 41 weeks or expected management up until 42 weeks. Correct? Absolutely. Yeah. And so, and I'll talk a little bit now about what the researchers found. So for the mothers, they found that the overall C-section rate was 10.5% in the induction group and 8.9% in the expected management group. And for people who were giving birth for the first time, the Caesarean rate was also lower in the expected management group compared to the other groups. And so, they were able to identify the preference group and the! And so, they found that the mother was also lower in the expected management group compared to the induction group. The combined measure of poor health outcomes for mothers was similar in both groups. 11.6% in the induction group versus 11.4% in the expected management group. And again, this was that same maternal composite adverse outcome rate. One maternal death occurred in the expected management group from an birth when the birthing person's bloodstream is exposed to amniotic fluid and they have a severe reaction. This type of exposure is really common in pregnancy, especially during late term and birth, there's all sorts of like fluid interchange between a birthing person and a baby. So, researchers are trying to understand why this occurs in some people, but doesn't occur in most others. Aside from that very serious and tragic outcome, five other women were admitted to the intensive care unit for from the unknown preference group and went from the expected management group and most of those admissions to the ICU were due to severe postpartum hemorrhage. So, for the babies, the findings in this study were that babies in the elective induction group had a lower composite adverse outcome rate of 1.1% versus 1.9% in the expected management group. No silvers occurred in this study while one neonatal death occurred the day of birth in the unknown preference group. And the infant who died was born to somebody who went in spontaneous labor at 41 weeks, two days and experienced a sudden excessive loss of blood after their water broke and the baby's heart rate slowed. They had an emergency cesarean and the baby died later due to complications of a lack of oxygen. So, in summary, this companion study to the index trial found a lower rate of cesareans for those who chose expected management. They also observed a similar rate of poor maternal health outcomes with induction versus expected management. Those who chose an elective induction at 41 weeks had fewer overall adverse outcomes for newborns. However, the absolute risk for adverse newborn outcomes was low in both groups. And interestingly, it was lower than the rates that they observed at the original index trial. So, that was the index trial is one of the big important recent studies that came out on this topic. Rebecca, would you like to walk us through sweepers? Yeah, so sweepers is the other really large randomized control trial on induction at 41 weeks. And it stands for the Swedish postterm induction study. SWEPIS is the acronym. It gained a lot of media attention when it was published. There were headlines such as postterm pregnancy research canceled after six babies die. And the truth is, you know, there were serious things that happened during this study. The researchers planned to enroll 10,000 mothers from multiple health care centers across Sweden, but they ended up stopping the study early with about 1,380 people in each group. After their data safety and monitoring board found a significant difference in stillbirths and newborn deaths between groups. So similar to the Netherlands when index was trialed out, midwives in Sweden at this time did not typically induce labor before 42 weeks and healthy pregnancies and also like the Netherlands, midwives in Sweden manage most pregnancies and births. So the investigators for SWEPIS wanted to compare elective induction at 41 weeks and zero to two days versus expectant management and induction at 42 weeks and zero to one day if the person still had not gone into labor. So they enrolled mothers between 2015 and 2018 being the study you had to be healthy, pregnant with a single head down baby. And gestational age was required to be estimated with an ultrasound from the first or second trimester. They excluded lots of people such as those with prior caesarean or those who had complications such as diabetes, high blood pressure, small for gestational age babies and other complications. So because the stillbirth rate in Sweden is so low, they typically have really good outcomes there. They thought they would need about 10,000 people overall to see a difference in these two interventions, but they ended up not needing that many people to see a difference in outcomes. And that's why the study was stopped early. So a big strength of the SWEPIS trial is that they did define their induction protocol and they use the same protocol in both groups. So if you had an induction in the elective induction group or in the expected management group, you would have similar protocols for the induction. And that included if your cervix was already ripened and ready for labor, then they would simply break your water and start synthetic oxytocin, aka pitocin. If your cervix was not ripe or your baby's head was not engaged, then they would do cervical ripening. First, they might use mechanical methods or medications, and then they would give the synthetic oxytocin after the cervix was ripened. So in the elective induction group, the people who are supposed to have that induction, 14% did go into labor on their own before their scheduled induction. And 86% actually had the induction. And in the expected management group, 67% went into labor spontaneously before their planned induction date and 33% were induced. So similar to the index trial, the median decrease and the length of pregnancy between the groups was very short. So pregnancy in the elective induction group was in general only about three days shorter than those who had expected management. Oh, wow. That's so interesting. So like in the index study, the elective induction group gave birth only a few days earlier than average. So Rebecca, what did the sweepers investigators find? So as I mentioned earlier, the study was stopped early. There were five stillbirths and one early newborn death in the expectant management group out of 1,379 participants in that group. That gives us a death rate of 4.4 deaths per 1,000 deliveries. In contrast, there were zero deaths in the elective induction group out of 1,381 participants in that group. All five of the stillbirths in the expectant management group occurred between 41 weeks, two days and 41 weeks, six days. Three of those five stillbirths had no known explanation. One stillbirth had a baby who was small for gestational age, which we already discussed can be a risk factor for stillbirth. And the other stillbirth was a baby who had a heart birth defect. And then the one newborn death occurred four days after birth due to multiple organ failure and a baby who was born large for gestational age. So the authors were trying to kind of talk about what happened here. And they mentioned that, you know, when there might be complications present in the pregnancy, maybe something with the placenta or the umbilical cord, that those differences might become increasingly important as the days of pregnancy progress past 41 weeks, leading to that higher death rate with expectant management past the 41 week time point. And another thing to note is that all of these perinatal deaths, all of these losses were to babies who were being born to first time mothers, which suggests that a 41 week induction might be especially beneficial if you're giving birth to your first baby. And they calculated that it would take only 230 elective inductions at 41 weeks to prevent one stillbirth or newborn death. And this is a much lower number than previously thought that it doesn't take as many inductions to save one life. Now, I know, Sarah, when you were talking about the index trial, they did not find a significant difference in perinatal death between the induction group and the expectant management group. And I think some of the reasons why they did see a difference in sweepers is sweepers was a larger study. So it's better able to detect rare outcomes such as death. And it also could be that in the index trial, they had better fetal monitoring going on during that 41 week time period when people were waiting up until 42 weeks to have their baby, possibly leading to fewer perinatal deaths. We can't be certain because there were no published fetal monitoring protocols in either trial. Finally, the participants in the sweepers expectant management group tended to give birth a little bit later than the participants in the index expectant management group. And that might help explain the higher perinatal death rate in sweepers. When they looked at the combined perinatal outcome of severe health outcomes in babies or death, there was no significant difference between the two groups. It was about 2.2 to 2.4% in both groups. However, there was that significant difference in just looking at the death rate. The elective induction group babies were less likely to be admitted to the NICU 4% versus 5.9% had fewer cases of jaundice 1.2% versus 2.3% and there were fewer big babies in the elective induction group 4.9% versus 8.3%. For mothers in sweepers, there was no meaningful difference since the serine rates between groups is about 10 to 11% in both groups. More mothers in the elective induction group had a type of infection called endometritis, which is inflammation of the inner lining of the uterus. That was 1.3% versus 0.4%. Meanwhile, there were more mothers in the expectant management group that developed high blood pressure disorders at the end of pregnancy. 3% versus 1.4%. There were no cases of uterine rupture in either group. And when they asked people about their experiences, they found that people in the expectant management group struggled more with negative thoughts. They described feeling in limbo or kind of stuck while they waited for labor or 42 week induction. And as I mentioned, the fetal monitoring in sweepers was done per local guidelines because there was no published study protocol for how to monitor the fetus while you're waiting for labor. However, the mothers recruited in the Stockholm region of Sweden, which was about half the people in the study did have a specific protocol, because that's what was typically done in that area where they measured amniotic fluid volume in abdominal diameter right at 41 weeks. And that assessment was not really done in the other parts of the country where the study was taking place. And so important to note from the study is that none of the six deaths occurred in the Stockholm region of Sweden where they were doing this type of prenatal fetal monitoring. So this could mean that the results of the study might not apply equally to a place that's doing more intensive fetal monitoring to make sure everything's okay with the fetus while you wait for labor to begin. Also, since all of the perinatal deaths were happening in cases where it was a first time birth and the mother had not given birth before, the study results might not apply to those who have given birth before. Yeah, I thought the results of this study were really interesting. And of course, it garnered so much attention for some of the outcomes that occurred. Could you share with the listeners what, if any impact the study had on induction of labor in the country where the study took place? Sweden? Yeah. So there has been follow up research on induction in Sweden after sweep. This really ignited debate in Sweden, but also in other places around the world about, you know, when should we induce labor? Is this 41 week time point really important? And in Sweden, they changed our national guidelines to recommend an induction at 41 weeks to offer that to everyone or to have an individual plan aiming at birth or inducing labor by 42 weeks. And so there was a study published in 2025 comparing outcomes like pre and post these guidelines change. So they looked at all of the births that happened at pre sweepers and then all of the births that happened post sweepers. And they were primarily interested in rates of stillbirth in newborn death, as well as overall other bad health outcomes for babies and caesarean rates. Overall, they found that the risk of stillbirth in newborn death to babies born at or beyond 41 weeks decreased from pre sweepers to post sweepers from about 1.7 per 1000 infants down to 0.9 per 1000 infants. And there were also lower rates of birth trauma and a lower risk of stillbirth in newborn death for babies who were born in the 39 to 40 week time period. Meanwhile, they did see induction rates go up slightly. The rate of severe tears went down slightly and women's experiences of childbirth were slightly better post sweepers. So a little bit mixed results, but overall it seemed like this research did translate into better outcomes for babies after the guidelines were changed. So we've gone over index and sweepers and some of like the results we've seen from those major studies and their follow up studies. There are also a few other smaller studies that you can see if you review the full signature article, as well as a table in the signature article. It kind of goes over each of the individual studies. So if you want to dive in and learn more, all of the data are there for you. So I thought now, sorry, we could go over the benefits and risks of induction focusing at that 41 week time point. If it's okay with you, I'll read the potential benefits and you can share the potential risks. Sound good? Sounds great. Okay. So when we're looking at scheduling and induction at 41 weeks, the research does show that one of the main benefits is a lower risk of stillbirth, especially among those who have risk factors for stillbirth. One of those risk factors is being pregnant with your first baby. And the overall or absolute risk of stillbirth is four out of 10,000 pregnancies of 39 weeks, seven out of 10,000 pregnancies at 40 weeks, 17 out of 10,000 pregnancies at 41 weeks and 32 out of 10,000 pregnancies at 42 weeks. So you can see how that inducing labor closer to that 41 week zero time point would be important because of that increased in risk in the 41st week of pregnancy. Other potential benefits include a lower risk of a baby needing intensive care unit admission, a lower risk of the baby experiencing jaundice, the lower chances of giving birth to a big baby, potentially a lower risk of cesarean, depending on the practice setting and how well the practitioners do with providing inductions and lowering the risk of cesarean with inductions. Another consistent finding in the research is that there's a lower risk of developing a high blood pressure disorder than the pregnancy and cognitive benefits for babies during a continued pregnancy appear to increase until about 40 to 41 weeks of pregnancy. So you're getting kind of like the full benefit of the baby's development in the womb. If you go up to 41 weeks and that's another reason researchers think that is a good time point to go ahead and do an elective induction. And then finally, a lot of people find that a potential benefit for them is the convenience and also the ability to end pregnancy. Once you're becoming really uncomfortable and researchers have found that in general satisfaction tends to go up when the timing of birth is 41 weeks rather than 42 weeks. Okay. So those were the pros. And now I'll talk a little bit about the cons. So some of the cons that we identified from the research was that when a potential for the medicalization of birth because of the induction, so continuous field monitoring, sometimes what people refer to as a cascade of interventions that could occur to the potential for a failed induction leading to a cesarean, the potential for uterine tachycystal, more than five contractions and 10 minutes averaged over a 30 minute window, a potential increase in risk of uterine rupture with medical induction, especially among those who have had a previous cesarean missing out on the hormonal benefits of spontaneous labor, increased risk of the mother experiencing the inflammation of the inner lining of the uterus, that endometritis infection that Rebecca referenced earlier. And medically induced contractions can potentially increase pain and make it more likely that the person would choose to also use a epidural. Sarah, I know you also updated the section on this article about, you know, what do the published guidelines say about induction past your due date? Can you share some of those guideline recommendations with us? Yeah. So for this update, we found recent guideline recommendations about induction at 41 weeks or later from the American College of Obstetricians and Gynecologists, the American College of Nurse Midwives, the Society of Obstetricians and Gynecologists of Canada, the Association of Ontario Midwives, and the National Institute for Healthcare Excellence Guidelines in the UK. You can see the actual breakdown by publication in the signature article, but the overall trends were that as a pregnancy continues beyond 41 weeks, most guidelines begin to recommend that providers have discussions with their patients about the benefits and risks of inducing labor versus expected management. They also began to recommend increased fetal monitoring if expected management is chosen at 41 weeks and later. The recommendations for 42 weeks trend towards recommending induction if labor has not yet started on its own. If a patient chooses expected management at 42 weeks or later in pregnancy, recommendations then suggest regular fetal monitoring until birth. Fetal monitoring cannot always prevent complications for occurring, nor will it always catch a complication as it's happening. But the hope with that recommendation is that providers can interpret these results and share this information with their clients to promote informed choice and to promote shared decision making. So Rebecca, do we have time to do a couple frequently asked questions that we get on this topic? Yeah, let's do two. So one question that comes up on this topic is what about induction for going past your due date and someone who is planning a V-BAC? So we hear this a lot, but many people who are planning a vaginal birth after cesarean or V-BAC are told they must go into labor by 39 weeks, or maybe they're told 40 or 41 weeks, or they're required to have a repeat cesarean, or sometimes they'll say you can have an induction, but not always. Sometimes it's just you have to have a cesarean. So researchers have found that only about 10% of people who reach term will spontaneously give birth by 39 weeks in zero days. So if a hospital is mandating, you know, you have to have a repeat cesarean. If you haven't gone into labor by your 39th week, this means that 90% of people planning a V-BAC at that particular facility will be disqualified from having a spontaneous V-BAC labor. Also, some hospitals and providers will refuse to provide an induction with V-BAC because there is a higher risk of uterine rupture if you have had prior uterine surgery with an induction. So that means some people who reach their required deadline will only have one option and that's a repeat cesarean. There's actually no evidence supporting these hard stop rules that you must give birth by 39 weeks or you must give birth by 40 weeks if you're having a V-BAC. The first large meta-analysis to specifically look at the link between weeks of pregnancy and likelihood of V-BAC was published in 2019. They included 94 observational studies with nearly 240,000 people attempting labor for a V-BAC. And interestingly, they found that gestational week at birth was not linked to your odds of having a V-BAC. So whether you gave birth at 37 weeks, 39 weeks or 41 weeks, it didn't make a difference as to whether someone was having a V-BAC or not. And in another study, researchers looked at more than 12,000 people who were electively induced at 39 weeks who were having a V-BAC and compared them to those who were having expectant management beyond that date. They found that elective induction at 39 weeks was associated with a higher chance of ending up with a V-BAC, 74% versus about 60% for those who had expectant management, but there was also a higher chance of uterine rupture in the elective induction group. So in the induction group, the rate of uterine rupture was 1.4% versus 0.4 to 0.6% and those who chose expectant management. And importantly, the risk of uterine rupture did not go up for those who had expectant management and chose not to be induced. So at 39 weeks during labor, the risk was 0.5%. At 40 weeks, it was 0.6%. At 41 weeks, it was 0.4%. So that's the evidence we have on that. Another question is, are there any benefits to going past your due date? Sara, do you want to take that one? Yeah. So we talked a little bit about that earlier, but it's nice to be able to take some more time and really kind of dive in here. So one of the benefits to going past your due date and waiting for spontaneous labor, if that's your preference, is that you can avoid the potential risks of an induction in associated interventions by having a lower intervention labor and birth. The American College of Obstetricians and Gynecologists in partnership with the American College of Nurse Midwives wrote in a committee opinion that titled approaches to limit intervention during labor and birth. If you're interested in looking at it, that some common obstetric practices are of limited or uncertain benefit for low risk people and spontaneous labor. So if you don't have an induction, for example, you're not going to be exposed to certain risks that can come with that particular intervention, like having a failed induction, for example, uterine tachycystle. The uterine contractions are too close together, having an increased need for an epidural, things like that. A beneficial benefit of going past your due date and waiting for spontaneous start of labor is that you might experience hormonal benefits for allowing the normal process of labor to take place. And that's something that Dr. Sarah Buckley covers in her work, the Hormonal Physiology of Child Bearing. Based on the available evidence, Dr. Buckley concluded that, quote, overall consistent and coherent evidence from physiologic understandings and human and animal studies finds that the innate hormonal physiology of mothers and babies, when it's promoted, supported and protected, has significant benefits, both in child bearing and likely into the future by optimizing labor and birth, newborn transitions, breastfeeding, maternal adaptations and maternal infant attachment. Also, so another benefit that we've heard about anecdotally is that later term and postterm babies have an easier time with breastfeeding. There's not a lot of research on the subject, but we did find a recent study from New Zealand of around 1,087 women that compared labor and neonatal outcomes based on when an induction took place. You can see the details in the signature article, but what they found was that as babies were born later and later, they compared babies born in early term, full term and then late term. So 37 to 38 weeks, 39 to 40 weeks and then 41 weeks and later. The babies born late term, 41 weeks and later, were most likely of the three categories to initiate in sustained breastfeeding. There might also be cognitive benefits for babies when pregnancy continues to 40 or 41 weeks. A study of Scottish schoolchildren found that the need for special education was highest among children born before 37 weeks. And there was a continuous decrease in that need for special education using that as sort of a proxy for neurodevelopmental outcomes. Until 41 weeks, after which point, the risk quickly increased again. And the recent Cochrane review called for more research on this topic. It could be an important thing to consider. I do know one note here that these benefits, there's potential benefits are with going past your due date, are associated with going past your due date in a single uncomplicated pregnancy. And we cover a lot more in the article and we've really kind of only scratched the surface here. I'm really excited to share this review of the recent research because I know our readers and our professional members are especially so interested in the studies that they can look up and read for themselves. But I think we're at the end here, Rebecca. And because we're at the end, I feel like I should ask you, Rebecca, what's the bottom line? So what's the bottom line about inducing labor for reaching 41 weeks? Well, elective induction at 41 weeks and zero days could help reduce stillbirths and lower the risk of poor health outcomes for babies, especially among first time mothers. So importantly, we have two large randomized controlled trials published in 2019 that both found benefits to elective induction at 41 weeks instead of continuing to wait for labor until 42 weeks. Both of these trials took place in countries that follow the midwifery model of care and the overall cesarean rates were low amongst everybody in the study, generally about 10 to 11 percent. One of these two studies found that there were fewer newborn deaths and stillbirths with 41 week induction. And the other study did not find a difference in deaths, but it found fewer poor health outcomes for babies with 41 week induction as compared to waiting for one more week. If it seems like you're going past your due date, it's important to talk with your care provider about the potential benefits and risks of having an elective induction at different time points versus waiting for spontaneous labor for a certain period of time and then perhaps having an induction later if needed. So any conversation about induction should take into account your preferences, your personal birth history, risk factors for stillbirth, such as small for gestational age, which is a very important risk factor or it being your first birth, chances of the induction being successful, including how ripe your cervix is, your hospital's cesarean rate with inductions, how well do they do at lowering the cesarean risk with inductions? And what are some alternatives to the induction? I also think the bottom line includes that non medical factors are very real when it comes to individual decision making. For example, for some people, the experience of being induced might include potentially more painful contractions leading to being tethered for monitoring and IV fluids, more likely to need an epidural or being confined to bed. And those interventions might not make much of a difference to someone who's already planning to have multiple interventions in their birth, but it could make a big difference to someone who is planning to use movement, freedom of movement, freedom of eating and drinking and other comfort measures with an unmedicated birth. Another example of how individual preferences can come into play is if someone has experienced miscarriages or stillbirth in the past or has important risk factors for stillbirth, they may have a strong preference for elective induction in order to lower the overall risk of stillbirth by any means necessary. And I want to affirm that all these experiences and preferences are valid. So here at EBV, I hope you found this research helpful. All about the evidence on inducing labor for when you go past your due date and reach 41 weeks. We also cover 42 weeks in the article as well as another time point. Just go to ebberth.com slash inducing due dates and you can download a free handout all about the evidence on inducing for 41 weeks. And we have a lot of other resources available, all of the references. You can just click on the link and go straight to the studies that we talk about and resources that we share in there for stillbirth in newborn loss. So thank you, Sarah, for your hard work on this article. And I'm excited that we're getting it into everybody's hands and their ears today. Thank you. It's so much fun to get to talk about this and I'm so excited for people to read. And I hope it is helpful. Today's podcast was brought to you by the Signature Articles at Evidence Spacebirth. Did you know that we have more than 20 peer reviewed articles summarizing the evidence on childbirth topics available for free at evidence spacebirth.com? It takes six to nine months on average for our research team to write an article from start to finish. And we then make those articles freely available to the public on our blog. Check out our topics ranging from advanced maternal age to circumcision, due dates, big babies, pitocin, vitamin K, and more. Our mission is to get research evidence on childbirth into the hands of families and communities around the world. Just go to evidencebasedbirth.com, click on blog, and click on the filter to look at just the EVB Signature Articles.