Excluded from these two groups were people who were not electively induced initially, but waited for labor and then ended up having inductions later on, some of which were medically necessary and, thus, linked to a higher rate of Cesareans. For an example of this earlier flawed research, see this article by Yeast et al. New researchers pointed out that we need to compare people who have elective inductions with the whole group of those who wait for spontaneous labor—whether or not they actually do have spontaneous labor.
This is a subtle difference, but an important one, because not everyone who waits for labor will actually have a spontaneous labor; some will develop complications that lead to an induction and increase their risk for Cesarean. The researchers argued that the comparison group must include these people as well. So, with this new understanding, someone in the wait-for-labor group who ends up being induced later in the pregnancy would not be considered inappropriate crossover between groups.
This is because induction later in the pregnancy is a possible outcome with expectant management, just like going into spontaneous labor is a possible outcome. This graphic shows how you would look at the two groups: the elective induction group versus the entire group of people who were not electively induced at that time—some of whom would, in fact, end up being induced later in the pregnancy.
Basically, when they started using the appropriate comparison group in studies, they no longer saw the increase in Cesareans with elective induction. When someone gets closer or past their due date, they will often face the question about whether to induce labor or wait for labor to start on its own. Before we begin discussing the evidence, it is important to note that there are some major drawbacks to the evidence that we have so far on induction versus waiting for labor to start:.
In , researchers published the results of the ARRIVE study A Randomized Trial of Induction Versus Expectant Management , conducted to find out if elective induction of labor during the 39th week of pregnancy would result in a lower rate of death and serious complications for babies, compared to waiting until at least 40 weeks and 5 days for elective induction Grobman et al.
They also wanted to see if inductions had an effect on the risk of Cesareans. This was a large study that took place across 41 hospitals in the United States. Researchers screened more than 50, people to see if they could take part in the study. People had to be giving birth for the first time with a single, head-down baby, be certain of the date of their last menstrual period, and have no major medical conditions.
The researchers randomly assigned like flipping a coin 3, people to be induced at 39 weeks, and 3, people to expectant management. Expectant management meant you could wait for labor to begin on its own as long as birth occurred by 42 weeks and 2 days, or be induced for medical reasons at any time, or be induced electively after 40 weeks and 5 days.
In other words, people in the expectant management group experienced a mix of spontaneous labor, induced labor for medical reasons, and electively induced labor. Some people may wonder why the researchers did not simply compare elective induction with spontaneous labor.
As we discussed, they could not compare those two groups, because spontaneous labor is not a certainty—it is possible someone may change their mind and wish to be induced electively, or require an induction for medical reasons. They found that inducing labor at 39 weeks did not improve the primary outcome of death or serious complications for babies.
Since stillbirths and newborn deaths are very rare at 39 and 40 weeks, the ARRIVE study with 6, participants was too small to tell if elective induction has an effect on this outcome. More babies received breathing support after expectant management 4. Hopefully, researchers will publish another study based on the ARRIVE data called a secondary analysis that will give us a better understanding of why week induction led to a lower rate of Cesarean. The mothers in the early induction group spent more time in the hospital in labor, but less time in the hospital postpartum.
There was no difference in breastfeeding outcomes between groups. The study authors did not mandate a single protocol for induction or labor management, but it was recommended that providers follow best practices for induction, such as using cervical ripening for anyone who had an unfavorable cervix. The researchers think their finding on the Cesarean rate is explained by an increase in the risk of Cesarean the longer a pregnancy continues.
Longer pregnancies mean more opportunities for potential complications to show up and an increasing willingness by providers to perform a Cesarean. Some mothers may not benefit from early elective induction, including:. An important limitation to the ARRIVE trial is that it was not designed to look at the practical implications of inducing everyone at 39 weeks.
Increasing the number of elective inductions may increase costs and resources owing to a longer length of stay in the hospital before the birth. On the other hand, these costs could be offset by the costs required for expectant management more prenatal visits, monitoring, or treating complications.
Researchers have expressed concerns that filling beds with people choosing elective inductions could mean there is no space for those with severe preeclampsia or post-term pregnancy Marss et al.
That was the absolute risk of having a Cesarean, or how often Cesareans actually happened in each group. Absolute risk is the actual, or true risk of something happening to you. Relative risk is the risk of something happening to you in comparison to someone else, and you have to carry out a math formula to understand the reduction in relative risk. For example,. Miller et al. They found no difference in the rate of Cesareans between groups.
To put it another way, elective induction at 39 weeks was not found to significantly increase or decrease the Cesarean rate. This is more evidence that as the pregnancy progresses, there are more opportunities for complications to develop. The main benefits of expectant management past 39 weeks were more spontaneous labor and a shorter hospital stay for mothers: about 10 hours shorter, on average, compared to the induction group.
Another randomized trial by Walker et al. In brief, there was no difference in Cesarean rates between the induction at 39 weeks group and the not-induced-atweeks group. There was also no difference in any of the other birth complications for mothers or babies.
We found five retrospective studies conducted in the last five years that compared week elective induction with expectant management. A retrospective study is one that looks back at events that took place in the past. Four of the studies found a lower Cesarean rate with elective induction at 39 weeks compared to expectant management and one study found no difference in the Cesarean rate between groups.
All five of the studies found newborn benefits with elective induction at 39 weeks. The largest retrospective study California data from over , births, Darney et al. However, these studies are not randomized, so they have inherent flaws. For more details on these studies, see Table 1. We considered the evidence discussed above in a broader context to develop the following list of potential Pros and Cons of week elective induction. Two large randomized, controlled trials on post-term induction came out in They both found that week induction might improve outcomes for babies.
It was a multicenter trial, conducted at midwifery practices and 45 hospitals in the Netherlands, where midwives manage most pregnancies and births. The researchers randomly assigned a total of 1, pregnant people to either induction at 41 weeks and 0 to 1 days or to expectant management and induction at 42 weeks and 0 days if still no labor.
In the Netherlands, labor is not usually induced before 42 weeks with an uncomplicated pregnancy, so they were able to get ethical approval to conduct this study. Pregnant people were enrolled into the study between and Mothers had to be healthy and pregnant with single, head-down babies.
Everyone had to have a gestational age that was estimated with ultrasound before 16 weeks of pregnancy. In both groups, cervical ripening and induction methods depended on local protocol. This is an important weakness of the study because, like the large Hannah Post-Term trial, individual providers in the INDEX trial may have managed labor inductions differently based on group assignment.
Interestingly, the median decrease in length of pregnancy between groups was only two days. In other words, the median pregnancy was only 2 days shorter in the elective induction group, compared to the expectant management group.
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. In Sweden, just like in the Netherlands, labor is typically not induced before 42 weeks with uncomplicated pregnancies and midwives manage most pregnancies and births.
This study set out to compare elective induction at 41 weeks and 0 to 2 days versus expectant management and induction at 42 weeks and 0 to 1 day if still no labor. From to , researchers enrolled healthy mothers with single, head-down babies.
Gestational age had to be estimated with 1 st or 2 nd trimester ultrasound. They excluded anyone with a prior Cesarean, diabetes, low fluid levels, high blood pressure disorders, small-for-gestational-age babies, or known fetal malformations. There is a low stillbirth rate in Sweden, which is why they planned to enroll 10, people, but they ended up not needing nearly that many people to see a difference in perinatal outcomes between groups.
A big strength of the SWEPIS trial is that they defined an induction protocol, and the same protocol was used with the people assigned to elective induction and those assigned to expectant management who were induced for medical reasons or because the mother reached 42 weeks of pregnancy.
Similar to the INDEX trial, the median decrease in length of pregnancy between groups was very slim—pregnancy in the elective induction group was, in general, only 3 days shorter. As we mentioned, fetal monitoring in this study was done per local guidelines.
In other words, there was no study protocol for fetal monitoring during the 41 st week of pregnancy. The mothers recruited in the Stockholm region about half the people in the study had ultrasound measurement of amniotic fluid volume and abdominal diameter at 41 weeks, whereas such assessments were not regularly performed at the other centers. Importantly, none of the six deaths occurred in the Stockholm region of Sweden, where this type of fetal monitoring was performed.
This means that the results of the SWEPIS study may not apply equally to mothers who receive fetal monitoring during the 41 st week of pregnancy.
Also, since all of the perinatal deaths occurred to first-time mothers, the study results may not apply equally to experienced mothers. In a Cochrane review and meta-analysis, researchers compared people who were electively induced to those who waited for labor to start on its own Middleton et al. They included 30 randomized, controlled trials over 12, mothers comparing a policy of induction at or beyond term versus expectant management. The trials took place in Norway, China, Thailand, the U.
The Hannah Post-Term trial, which we will describe in detail, was the largest trial included. The Cochrane authors considered the overall evidence to be moderate quality. What did they find? The Hannah Post-Term trial excluded deaths due to fetal malformations, but some of the smaller trials did not. If we exclude the three deaths from severe fetal malformations, then there was one death in the induction group and 14 deaths in the expectant management group.
Overall, the number needed to treat was people with induction to prevent 1 perinatal death. Specifically, there were fewer stillbirths with a policy of induction 1 stillbirth versus The absolute risk of perinatal death was 3. A policy of induction was also linked to slightly fewer Cesareans compared to expectant management Fewer babies assigned to induction had Apgar scores less than 7 at 5 minutes compared to those assigned to expectant management. The authors concluded that individualized counseling might help pregnant people choose between elective induction at or beyond term or continuing to wait for labor, and that providers must honor their values and preferences.
We need more research to know who would or would not benefit from elective induction and the optimal time for induction is still not clear from the research.
This study was published in the New England Journal of Medicine. Between the years of to , a group of researchers enrolled 3, low-risk pregnant people from six different hospitals in Canada into the Hannah Post-Term study.
Participants were included if they had a live, single fetus, and were excluded if they were already 3 or more centimeters dilated, had a previous Cesarean, had pre-labor rupture of membranes, or had a medical reason for induction. The study took place in the six Canadian hospitals between the years and At around 41 weeks, participants were randomly assigned to either induction of labor or fetal monitoring expectant management.
There were two stillbirths in the group assigned to wait for labor and zero in the group assigned to induction, but this difference was not statistically significant. You can look at the outcomes for the two original groups—the people randomly assigned to induction and those assigned to fetal monitoring—or you can look at the breakdown of what actually happened to the people in the two groups.
In other words, what happened to the people who were actually induced or actually went into spontaneous labor? If you look at what happened in the two original groups random assignment to elective induction and expectant management groups , the overall Cesarean rate was lower in the elective induction group There was also a lower rate of Cesareans for fetal distress in the elective induction group versus the expectant management group 5. If instead of considering the results according to how participants were assigned—to the elective induction and or expectant management groups—you look at what actually happened to the people who were induced or who actually went into spontaneous labor, this is what you will see Hannah et al.
So, we see two very interesting things here: people who went into spontaneous labor, regardless of which group they were originally assigned, had a Cesarean rate of only The same pattern holds true when you look at experienced mothers people who had given birth before :.
Important details from the Hannah Post-Term study are hidden when you only look at the results according to random group assignment. The reported main findings were that a policy of fetal monitoring and expectant management increases the Cesarean rate.
But a closer look at the findings reveals that only the people who were expectantly managed but then had an induction later in the pregnancy had a really high Cesarean rate.
People who were expectantly managed and went into labor spontaneously did NOT have higher Cesarean rates. One possible explanation for the high Cesarean rate seen in the people who were assigned to expectant management and then ended up getting an induction is that the people in this group may have been at higher risk for Cesarean to begin with, since a medical complication could have led to the induction.
The people who were assigned to expectant management and never developed a complication requiring induction were the lower risk people, the ones less likely to give birth by Cesarean. Another factor that could have contributed to the high Cesarean rate in this group is the issue that we discussed previously—that doctors might have been quicker to call for a Cesarean when assisting the labors of people with medical inductions who had longer pregnancies.
If you are not having contractions after 24 hours, you may be offered another dose. Sometimes a hormone drip is needed to speed up the labour. Once labour starts, it should proceed normally, but it can sometimes take 24 to 48 hours to get you into labour.
Induced labour is usually more painful than labour that starts on its own, and you may want to ask for an epidural. Your pain relief options during labour are not restricted by being induced. You should have access to all the pain relief options usually available in the maternity unit. If you are induced you'll be more likely to have an assisted delivery, where forceps or ventouse suction are used to help the baby out. Your obstetrician and midwife will assess your condition and your baby's wellbeing, and you may be offered another induction or a caesarean section.
You may have heard that certain things can trigger labour, such as herbal supplements and having sex, but there's no evidence that these work.
Other methods that are not supported by scientific evidence include acupuncture , homeopathy , hot baths, castor oil and enemas. Having sex will not cause harm, but you should avoid having sex if your waters have broken as there's an increased risk of infection.
For more information on induction, you can read the NICE information for the public on induction of labour. You can find pregnancy and baby apps and tools in the NHS apps library. Page last reviewed: 12 November Next review due: 12 November Inducing labour. Merck Manual Professional Version. Bush M, et al.
Umbilical cord prolapse. Gabbe SG, et al. Abnormal labor and induction of labor. In: Obstetrics: Normal and Problem Pregnancies. Philadelphia, Pa. Cunningham FG, et al. Induction and augmentation of labor. In: Williams Obstetrics. New York, N. Butler Tobah Y expert opinion. Mayo Clinic, Rochester, Minn. May 22, See also Back labor Bathroom during labor: What if you have to go? Can vaginal tears during childbirth be prevented?
Mayo Clinic Press Check out these best-sellers and special offers on books and newsletters from Mayo Clinic. Reprint Permissions A single copy of these materials may be reprinted for noncommercial personal use only. By Carolyn Crist. Reuters Health - For late-term pregnancies, inducing labor at 41 weeks may be safer than waiting until week 42, a large Swedish study suggests. There were no other differences between the two groups in adverse outcomes for infants or mothers, so induction at 41 weeks should certainly be offered to mothers, the study team concludes.
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