Healthy Birth Practice #1: Let Labor Begin on Its Own

Abstract

Current evidence and professional organizations identify letting labor begin on its own as one of the most important strategies for promoting normal, physiologic birth. It also prevents iatrogenic prematurity and the need for high-tech medical interventions required for labor induction. Because the American College of Obstetricians and Gynecologists (ACOG) now states that it is reasonable for obstetric care providers to offer induction at 39 weeks to low-risk nulliparous women, it is more important than ever for childbirth educators to be familiar with best evidence on letting labor begin on its own.

It can be argued that the most powerful way that we can support the normal physiology of labor and birth is to let labor begin on its own. Virtually every definition and consensus statement on normal, physiologic birth includes “spontaneous onset of labor” (see Table 1).

TABLE 1. Definitions of Normal, Physiologic Birth.

Organization(s)	Statement	Cite
WHO	“We define normal birth as: spontaneous in onset, low-risk at the start of labour and remaining so throughout labour and delivery. The infant is born spontaneously in the vertex position between 37 and 42 completed weeks of pregnancy. After birth mother and infant are in good condition” (p. 1).	Technical Working Group and World Health Organization (1997)
ACNM, MANA, and NACPM	“A normal physiologic labor and birth is one that is powered by the innate human capacity of the woman and fetus.…Normal physiologic childbirth • is characterized by spontaneous onset and progression of labor…” (p. 2).	ACNM, MANA, and NACPM (2012)
ACOG Note: reVITALize definitions are also endorsed by the AAFP, ACNM, AWHONN, and the SMFM	Definition of physiologic childbirth: “Spontaneous labor and birth at term without the use of pharmacologic and/or mechanical interventions for labor stimulation or pain management throughout labor and birth” (p. 4).	ACOG (2014b)
SOGC, AWHONN Canada, CAM, CFPC, and SRPC	“A normal birth is spontaneous in onset, is lowrisk at the start of labour and remains so throughout labor and birth. The baby is born spontaneously in vertex position between 37 and 42 +0 completed weeks of pregnancy. Normal birth includes the opportunity for skintoskin holding and breastfeeding in the first hour after the birth” (p. 1).	SOGC, AWHONN Canada, CAM, CFPC, and SRPC (2008)

Note. AAFP = American Academy of Family Physicians; ACNM = American College of Nurse-Midwives; ACOG = American College of Obstetricians and Gynecologists; AWHONN = Association of Women's Health, Obstetric and Neonatal Nurses; AWHONN Canada = Association of Women's Health, Obstetric, and Neonatal Nurses of Canada; CAM = Canadian Association of Midwives; CFPC = College of Family Physicians of Canada; MANA = Midwives Alliance of North America; NACPM = National Association of Certified Professional Midwives; SMFM = Society for Maternal-Fetal Medicine; SOGC = Society of Obstetricians and Gynaecologists of Canada; SRPC = Society of Rural Physicians of Canada; WHO = World Health Organization. Because of limited space, the organizations quoted are limited to the WHO and the United States and Canadian organizations. If you are located in another country, check the professional organizations in your country for their definitions of “normal, physiologic birth.”

Until August of 2018, professional guidelines consistently recommended that, unless medically indicated, induction be avoided until 41–42 weeks of gestation. With the publication of the ARRIVE (A Randomized Trial of Induction Versus Expectant Management) trial (Grobman et al., 2018), the American College of Obstetricians and Gynecologists (ACOG) changed its guideline from recommending no inductions (without medical indication) until 41–42 weeks of gestation to stating that it is reasonable to offer induction to low-risk nulliparous women at 39 weeks after discussing the options thoroughly (ACOG, 2018).

According to birth statistics published by the Center for Disease Control and Prevention (CDC), one in five women in the United States was induced in 2000; that number rose to one in four in 2016. (Martin, Hamilton, Osterman, Driscoll, & Drake, 2018, table l-15; Martin, Hamilton, Ventura, Menacker, & Park, 2002, table 27). With ACOG now supporting elective induction at 39 weeks, it seems inevitable that induction rates will continue to rise.

This Healthy Birth Practice paper summarizes the current evidence on the merits of letting labor begin on its own and the risks and benefits of labor induction.

SUPPORTING THE NORMAL PHYSIOLOGY OF BIRTH

The most compelling reason to let labor begin on its own may be to allow the birth hormones to regulate labor and birth, breastfeeding, and attachment as Mother Nature intends. Most childbirth educators are familiar with the important roles that the four main birth hormones—oxytocin, endorphins, catecholamines, and prolactin—play during childbirth. But an important report by Sarah Buckley (Buckley, 2014) also details the critical roles that these four hormones have in preparing both mother and baby for labor and birth.

Oxytocin

Both blood levels of oxytocin and the number of oxytocin receptors throughout the mother's body increase as pregnancy advances. However, final surges in oxytocin and oxytocin receptors may not occur until the final days before the spontaneous start of labor (Buckley, 2014). Letting labor begin on its own with the optimal number of oxytocin receptors and amount of natural oxytocin on board increases the likelihood that labor and birth will progress optimally and that breastfeeding and attachment will get off to the best possible start.

In animal studies, there is a surge of maternal oxytocin in the 24 hours around the time of spontaneous labor (Ceanga, Spataru, & Zagrean, 2010). This surge of oxytocin is thought to transfer to the fetal brain via the placenta and the immature blood–brain barrier of the fetus. The oxytocin reduces oxygen requirements in the fetal brain, thus providing a neuroprotective effect for the fetal brain during labor. Animal studies also indicate that the administration of high levels of synthetic oxytocin reduces this neuroprotective effect and may increase fetal vulnerability to low levels of oxygen. The increased vulnerability to hypoxia with the administration of synthetic oxytocin may be one piece of the puzzle in explaining the association between labor induction and increased cases of cerebral palsy reported in Norway (Elkamil et al., 2011) and the association between labor induction and autism reported in North Carolina (Gregory, Anthopolos, Osgood, Grotegut, & Miranda, 2013).

Studies have shown an increased risk of postpartum hemorrhage in women who are induced or augmented with synthetic oxytocin (Belghiti et al., 2011; Buckley, 2014; Rooks, 2009). Prolonged administration of synthetic oxytocin may lead to reduced sensitivity of the oxytocin receptors (Belghiti et al., 2011). This reduced sensitivity along with the decreased number of oxytocin receptors and a decreased level of oxytocin in women who do not allow labor to begin all help to explain the increased risk for postpartum hemorrhage.

Endorphins

Like oxytocin and oxytocin receptors, endorphins and endorphin receptors also gradually increase during pregnancy. Several studies have shown that women who exercise regularly have higher levels of endorphins when they go into labor and report less labor pain than women who do not exercise regularly (Varrassi, Bazzano, & Edwards, 1989). Letting labor begin on its own and exercising regularly throughout pregnancy will allow women to begin labor with optimal levels of endorphins.

Catecholamines

Fetal catecholamines also increase in the weeks or days before the spontaneous start of labor. Catecholamines play a critical role in readying the fetal lungs for air breathing immediately after birth by reducing the amount of fluid in the lungs (Jain, 2006, p. 104; Jain & Eaton, 2006). Fetuses that do not have this advantage because of scheduled cesarean surgery or induction of labor are at higher risk for respiratory problems at birth and admission to the neonatal intensive care unit.

Prolactin

Dr. Buckley shares studies that indicate that, like oxytocin and endorphins, prolactin levels increase throughout pregnancy, with steep increases at term. In animal studies, there is a large increase in prolactin receptors the day before the onset of spontaneous labor. Not only is prolactin critical in establishing breastfeeding, but it is also thought that late-gestation prolactin plays a role in helping fetal lungs to mature and in helping the baby to regulate his temperature after birth.

With levels of oxytocin, catecholamines, and prolactin sharply increasing around the time of spontaneous onset of labor, it is clear that waiting for labor to begin on its own will result in both the mother and the fetus having optimal levels of these important birth hormones. With optimal levels of the birth hormones, the baby is physiologically ready for extrauterine life, labor is more likely to progress well, breastfeeding is easier and more successful, and attachment is enhanced.

Variation in the Length of Human Gestation

It is well known that women do not always accurately remember the dates of their last menstrual periods (LMP), nor do all pregnant women have ultrasounds before 20 weeks to confirm due dates. In addition to misestimating the due date because of faulty memory or the lack of an early sonogram, there is another reason that scheduling the baby's birth ahead of time may result in a baby who is born “too early”: there appears to be a wide variation in the length of human gestation. In a prospective cohort study published in Human Reproduction in 2013, researchers followed 221 healthy women with no known fertility problems who discontinued contraception in order to become pregnant (Jukic, Baird, Weinberg, McConnaughey, & Wilcox, 2013). The women kept diaries and collected daily first-morning urine specimens for 6 months, or through the 8th week past LMP if they conceived. Researchers measured hormone levels in the urine specimens to determine the exact date of ovulation. One hundred and thirty conceptions during the study resulted in singleton live births. After exclusions, including for preterm births, researchers found that ovulation-based gestation ranged from 247 to 284 days—a span of 37 days or over 5 weeks! Using the traditional method of dating pregnancies from the last menstrual cycle, the pregnancies lasted from a little over 37 weeks to a little over 42 1/2 weeks. Although researchers cautioned that results may not be generalizable to more diverse populations, they recommended that a pregnant woman be given a range of due dates rather than just one specific day.

This research is consistent with Dr. Gordon Smith's classic research on the normal duration of human pregnancy. He found that only about half of nulliparous women will have their babies by 40 weeks and 5 days. Seventy-five percent will give birth by 41 weeks and 2 days (Dekker, 2016; Smith, 2001).

Figure 1.

Late preterm (34–36 weeks) births in the United States.

The Baby Initiates Labor

Many scientists now believe that it is the baby who initiates the labor process. Researchers at UT Southwestern Medical School identified two proteins in the fetal lungs that promote the initiation of labor once surfactant has been produced to ready the fetal lungs for air breathing at birth (Gao et al., 2015).

Thus, the best way to know that the baby is fully mature is to wait for the baby to initiate the labor process. With a possible natural 5-week variation in the natural length of normal gestation, some babies may be fully mature at 38 weeks while others need a few more weeks to become fully mature at 40 or even 42 weeks.

Preventing Iatrogenic Prematurity

If routine induction at 39 weeks is widely adopted, it is inevitable that some inductions will be performed before the fetus has actually reached 39 weeks gestation, either due to miscalculation of the due date or to scheduling errors. These newborns may be born early term (37 0/7–38 6/7 weeks) or even late-preterm (34 0/7–36 6/7 weeks). In an analysis of the dramatic increase in late-preterm births between 1990 and 2006 in the United States, epidemiologists for the National Center for Health Statistics stated that, “studies suggest that the increasing use of induction of labor and cesarean surgery at 34–36 weeks has influenced the upswing in the late preterm birth rate” (Martin, Kirmeyer, Osterman, & Shepherd, 2009, pp. 5–6). As evidence mounted of the increased risks to babies born late-preterm, the Joint Commission in 2010 asked hospitals to voluntarily report the number of elective births before 39 weeks as one of the perinatal quality measures with the goal of eliminating such births. Many hospitals banned all elective births before 39 weeks. Efforts to decrease elective late-preterm births were successful from 2006 through 2013. However, since 2014, late-preterm births have increased slightly each year (Martin & Osterman, 2018, p.1).

Risks for Early Term Babies

Even babies born just a few weeks early are at higher risk for increased mortality and morbidity. CDC researchers found that babies born early term (37–38 weeks) have mortality rates that were almost two-thirds higher than those born 39–41 weeks gestation (Mathews & MacDorman, 2013, p. 2). According to ACOG, babies born at 37–38 weeks gestation are at increased risk for respiratory distress syndrome, transient tachypnea, ventilator use, pneumonia, respiratory failure, neonatal intensive care unit (NICU) admission, hypoglycemia, 5-minute Apgar scores less than 7, and neonatal mortality (ACOG, 2013).

Risks for Late-Preterm Babies

In a review of the literature published in 2016, researchers found that babies born late-preterm (between 34 0/7 and 36 6/7 weeks) are at higher risk for respiratory morbidity, apnea, temperature instability, hypoglycemia, jaundice, and feeding difficulty (Natarajan & Shankaran, 2016). A sobering statistic is that a baby born late-preterm is three times more likely to die in the first year of life than a baby born full term (Mathews & MacDorman, 2013). In addition to increased morbidity and mortality, there is growing evidence that babies born late-preterm are at increased risk for long-term subtle neurodevelopment problems such as inferior academic performance and behavioral problems (Kugelman & Colin, 2013).

Changing the Experience of Labor and Birth

When labor begins on its own and the pregnancy and labor are considered low risk, routine medical interventions are not recommended. Laboring women can labor out of bed, use a wide variety of nonpharmacologic pain management strategies, including a warm tub, and choose their own position and method for pushing (ACOG, 2019; WHO, 2018). Intermittent fetal monitoring is preferred (American College of Nurse-Midwives [ACNM], 2015; SOGC, 2018, p. 2; WHO, 2018).

According to a meta-analysis published by the National Institute for Health Research in the United Kingdom, the administration of intravenous (IV) synthetic oxytocin (known as Pitocin in the United States and Canada) is the most common method of induction used worldwide (Alfirevic et al., 2016, p. 4). Obviously, IV fluids are required when labor is induced with IV Pitocin. Because there is an increased risk for uterine tachysystole and neonatal morbidity with the administration of artificial oxytocin, continuous electronic fetal heart rate monitoring (EFM) is also required. Continuous electronic fetal monitoring increases the risk for cesarean surgery. The combination of IV fluids and continuous EFM limits the ability of the laboring woman to move and change positions and limits her choice of comfort measures. Pitocin-generated contractions may peak more quickly and last longer than natural contractions, increasing the likelihood that the laboring mother will request epidural analgesia for pain relief. With epidural analgesia, some women have problems emptying their bladders, so that there is a possible need for a urinary catheter. Although there is controversy as to whether epidural analgesia by itself increases the risk of cesarean, Figure 2 powerfully illustrates the association of labor induction and epidural analgesia with cesarean surgery in the women polled in the Listening to Mothers III Survey, a survey of the birth experiences of women in the United States in 2011 and 2012 (Declercq, Sakala, Corry, Applebaum, & Herrlich, 2013).

Figure 2.

Cesarean rates of women in the Listening to Mothers III Survey.

Base: first-time mothers with term births who experienced labor n = 750. In this group, which included 85% of first-time mothers, the overall epidural rate was 69% and the overall cesarean rate was 21%. Reproduced with permission form Declercq, E.R., Sakala, C., Corry, M.P., Applebaum, S. & Herrlich, A. (2013). Listening to Mothers III: Pregnancy and childbirth. New York, NY: Childbirth Connection, now a part of the National Partnership for Women & Families, www.nationalpartnership.org.

A woman who chooses induction should be prepared for a long labor—particularly if her cervix is unripe—as ACOG recommends allowing 24 hours or more for latent labor and at least 12–18 hours of Pitocin administration. Although some methods of labor induction, such as induction with a foley catheter, require fewer additional interventions, all induction methods have possible side effects and may eventually require the administration of synthetic oxytocin.

Additional Risks Associated With Labor Induction

Swiss researchers compared obstetrical and neonatal outcomes in elective and medically indicated labor inductions done at term (Baud, Rouiller, Hohlfeld, Tolsa, & Vial, 2013). Both groups were also compared to women with spontaneous onset of labor. They found no significant differences in outcomes between the elective and medically indicated induction groups. Compared to women with spontaneous onset of labor, women who were induced at term were at greater risk for cesarean surgery, instrumental birth, postpartum hemorrhage greater than 500 mL, and prolonged maternal hospitalization (greater than 6 days). The babies of the mothers who were induced were at greater risk of arterial umbilical cord pH of less than 7.1, admission to the NICU, and prolonged NICU hospitalization (more than 7 days).

As mentioned earlier in this article, labor is most often induced by administering IV Pitocin (synthetic oxytocin). IV Pitocin is one of only 12 specific medications named to the “High-Alert” list by the Institute for Safe Medication Practices (Institute for Safe Medication Practices [ISMP], 2014). According to ISMP, “High Alert” medications are drugs that bear a heightened risk of causing significant patient harm when they are used in error. Indeed, approximately half of all paid obstetric litigation claims involve allegations of oxytocin misuse (Rooks, 2009).

The Association Between Induction and the Risk for Cesarean

Until recently, one of the most controversial issues in maternity care has been whether or not induction increases or decreases the risk for cesarean. In their 2009 ACOG Practice Bulletin, the authors stated, “… Nulliparous women undergoing induction of labor with unfavorable cervices should be counseled about a two-fold increased risk of cesarean delivery” (ACOG, 2009, p. 389). Several studies published since 2009 have found that induction either does not impact the risk for cesarean or may actually decrease the risk (Mishanina et al., 2014; Saccone & Berghella, 2015). In 2018, two major studies came to opposite conclusions when looking at the effects of routine induction on the risk for cesarean.

The ARRIVE Trial

To determine whether routine induction at 39 weeks of gestation improves neonatal and maternal outcomes, a randomized controlled trial of approximately 6,000 women was carried out from 2014 until 2017 in 41 hospitals across the United States (Grobman et al., 2018).

The randomized controlled trial (RCT) compared low-risk nulliparous women assigned to be induced at 39 0/7 weeks to 39 4/7 weeks (routine induction group) to a similar group of women who were assigned either to go into labor spontaneously or to be induced between 40 5/7 weeks and 42 2/7 weeks (expectant management group). After the study was completed, researchers found that the median gestational age for the induction group was 39.3 weeks and for the expectant management group, 40.0 weeks. The primary outcome was a composite of adverse perinatal events; the secondary outcome was cesarean surgery. Researchers found no significant difference between the two groups in the composite of adverse perinatal events and a small reduction in the cesarean rate from 22.2% in the expectant management group to 18.6% in the routine induction group.

There are concerns about the generalizability of this study and some experts have questioned whether routine inductions in all settings will lower the risk for cesarean surgery.

For the trial, 50,581 women were evaluated for eligibility. Of the 22,981 women who met eligibility criteria, 71% (16,427) declined to participate. The study authors do not describe the way in which the trial participants were different from the general population of women who gave birth in the United States in 2016. However, in an accompanying editorial in the same journal, Dr. Michael F. Greene describes the differences (Greene, 2018). Based on data from a National Vital Statistics Report (Martin et al., 2018), the trial participants were younger (median age of 23–24 versus a mean age of 28.7 for all U.S. mothers); were less likely to be older (only 4.1% of trial participants were 35 or older versus 17% for all mothers); and were less likely to be White and more likely to be Black or Hispanic than all mothers.

The cesarean rates in both groups (induction group, 18.6% and expectant management group, 22.2%) were lower than the national low-risk cesarean rates of 26% in 2017; 25.7% in 2016; 25.8% in 2015; and 26% in 2014 (Hamilton, Martin, Osterman, Curtin, & Mathews, 2015, p. 2; Hamilton, Martin, Osterman, Driscoll, & Rossen, 2018, p. 1; Martin et al., 2018, p. 7; Martin, Hamilton, Osterman, Driscoll, & Mathews, 2017, p. 2). This is most likely due to the fact that providers in the trial were encouraged to allow at least 12 hours in the latent phase after completion of any cervical ripening, rupture of membranes, and administration of oxytocin before concluding the induction had failed and deciding on cesarean surgery. Providers may not always exhibit such patience, thus increasing cesarean rates with induction.

There are only 5 days difference in the median birth date of 39.3 weeks gestation for the induction group and 40.0 weeks of gestation in the expectant management group. The difference in the cesarean rates between the two groups was only 3.6%. There is no information in the study about the ways in which labor was managed. There are many evidence-based strategies such as continuous support during labor that have a greater impact in reducing cesarean rates (Dekker, 2018).

There are some additional concerns about this study. There were a couple of “scheduling errors” that resulted in pregnant women having inductions before 39 0/7 weeks. For this study, the number was small, but if routine induction at 39 weeks is widely adopted, there certainly will be many more unintended early term and possibly late-preterm births.

For women who require cervical ripening, adhering to the recommended protocols in the August 2018 ACOG practice advisory may mean that labor lasts for more than 42 hours (ACOG, 2018). Longer induced labors will impact room availability and nursing hours (Main & the CMQCC Leadership Team, 2018).

As mentioned earlier, based on the results of this study, ACOG issued a practice advisory endorsed by the Society for Maternal-Fetal Medicine (SMFM) stating that it is reasonable for obstetric care providers to offer labor induction at 39 weeks to low-risk nulliparous women with confirmed due dates. ACOG and SMFM state that,

… Cesarean births for failed induction of labor in the latent phase can be avoided by allowing longer durations of the latent phase (up to 24 hours or longer) and requiring that oxytocin be administered for at least 12–18 hours after membrane rupture before deeming the induction a failure. (ACOG, 2018, p. 2)

On the other hand, following the publication of the ARRIVE trial, the American College of Nurse-Midwives (ACNM) reaffirmed its commitment to promoting normal, physiologic birth (ACNM, 2018), which they define in other publications as including the spontaneous onset of labor (ACNM, 2013).

The JBI Systematic Review

Also published in 2018, this systematic review by Danish researchers looked at maternal and fetal outcomes in studies comparing routine induction for low-risk women at 41 + 1–6 gestational weeks (induction group) to routine induction for similar group of women 42 + 1–6 gestational weeks (expectant mangement group) (Rydahl, Eriken, & Juhl, 2018). The induction group was composed of those who were induced at 41 + 0–6 gestional weeks; the expectant management group included all noninduced births between 41 + 0 and 42 + 6 gestational weeks and all births at 42 + 0–6 gestational weeks. The researchers chose this comparison because of the worldwide trend of inducing women for postdates at 41 rather than at 42 weeks. The methodology used is notable because the expectant management group included women who went into labor spontaneously during the 41st week and excluded women whose pregnancies reached or exceeded 42 completed weeks. The researchers found that routine induction at 41 + 0–6 weeks (induction group) was associated with an increased risk for cesarean surgery, labor dystocia, chorioamnionitis, precipitate labor, uterine rupture, and low pH in the newborn. Routine induction at 42 + 0–6 weeks (expectant management group) was associated with an increased risk of meconium stained fluid and oligohydramnios. The researchers concluded:

Our findings do not support the widespread use of induction prior to post-term, and they highlight the importance of discussing whether the threshold has been reached where risks related to the procedure of induction outweigh potential harms from the ongoing pregnancy, and whether induction of labor should be applied to large populations of low-risk women. (Rydahl et al., 2019, p.189)

Most pregnant women are tired, uncomfortable, and anxious to meet their babies as they get closer to their due dates. It is important for childbirth educators to provide best evidence about the merits of letting labor begin on its own and the experience of labor induction.

Medical Indications for Induction

There are times when it is better for a baby to be born than to stay inside the uterus. According to the ACOG, the following are possible medical indications for induction (ACOG, 2009, p. 389):

Abruptio placentae; Chorioamnionitis; Fetal demise; Gestational hypertension; Preeclampsia, eclampsia; Premature rupture of membranes; Post-term pregnancy; Maternal medical conditions (e.g., diabetes mellitus, renal disease, chronic pulmonary disease, chronic hypertension, antiphospholipid syndrome); Fetal compromise (e.g., severe fetal growth restriction, isoimmunization, oligohydramnios).

Fetal macrosomia is not listed as a medical indication for induction. In their 2016 practice bulletin on fetal macrosomia, ACOG provides this recommendation,

Suspected fetal macrosomia is not an indication for induction of labor because induction does not improve maternal or fetal outcomes. (ACOG, 2016, p. 203)

However, in the Listening to Mothers III Survey, 60% of the women believed that macrosomia is an appropriate reason for induction. Childbirth educators frequently hear that students are scheduling inductions because the baby appears to be “too big.”

There is controversy about whether oligohydramnios (too little fluid) by itself, without other symptoms of fetal compromise, is an appropriate indication for labor induction. Experts do not agree about the best method of measuring amniotic fluid; nor do they agree how much amniotic fluid is “too little.” According to a 2016 meta-analysis looking at isolated oligohydramnios as an indication for labor induction,

There is simply no evidence to support or defy routine labor induction. … (Shrem, Nagawkar, Hallak, & Walfisch, 2016, p. 172)

In the one randomized controlled trial that the researchers included in their systematic review, there were no significant differences in any important maternal or neonatal outcomes between the group that was induced and the expectant management group (Shrem et al., 2016).

When to Induce for Postterm Pregnancies?

Although experts define pregnancies lasting between 37 and 42 weeks as “term” and as “normal,” some health care providers and organizations, including WHO, recommend routine induction for postterm pregnancies at 41 completed weeks (WHO, 2011). However, there is also strong support for waiting until 42 completed weeks to routinely induce for postterm pregnancies.

In the latest Cochrane Review on induction for improving birth outcomes (Middleton, Shepherd, & Crowther, abstract, 2018), researchers analyzed trials that compared induction at or later than term with expectant management or waiting for a specified time to induce labor.

The Cochrane Review concluded that:

A policy of labour induction compared with expectant management is associated with fewer deaths of babies and fewer caesarean sections; but more assisted vaginal births. Although the chances of babies dying are small, it may help to offer women appropriate counseling to make an informed choice between induction of labour for pregnancies at, or later than, term — or waiting for labour to start and/or waiting before inducing labour. The best time to offer induction of labour to women at or beyond term is not yet clear and warrants further investigation. (Middleton et al., 2018, abstract, pp. 4–5)

Although the Cochrane Review is unable to answer the question, 41 or 42 weeks?, ACOG provides the following recommendations in their 2014 committee opinion, Management of Late-Term and Postterm Pregnancies (ACOG, 2014a):

Level A conclusion (based on good and consistent scientific evidence): “Induction of labor after 42 0/7 weeks and by 42 6/7 weeks of gestation is recommended, given evidence of an increase in perinatal morbidity and mortality.”

Level B conclusion (based on limited or inconsistent scientific evidence): “Induction of labor between 41 0/7 weeks and 42 0/7 weeks can be considered.” (ACOG, 2014a, p. 393)

The authors of the prestigious Williams Obstetrics also recommend induction for postterm babies with no other complications at 42 completed weeks (42 0/7–42 6/7 weeks) of gestation:

At Parkland Hospital, based on results from the trials just discussed, we consider 41-week pregnancies without other complications to be normal. Thus, no interventions are practiced solely based on fetal age until 42 completed weeks. (Cunningham et al., 2018, p. 841)

The JBI meta-analysis discussed in the section of this paper on the association of routine induction with the risk for cesarean also supports routine induction for postterm pregnancies at 42 completed weeks rather than 41 weeks (Rydahl et al., 2018).

A policy of waiting until 42 weeks will allow most healthy women to go into labor spontaneously since it is estimated that only 10% of pregnancies naturally go past 42 weeks (294 days) (Bergsjo, Denman, Hoffman, & Meirik, 1990).

How Can the Laboring Woman Who Needs an Induction for Medical Reasons Keep Labor as Normal as Possible and Maximize the Release of Birth Hormones?

Allowing the pregnancy to continue for as long as possible will help to increase the levels of the birth hormones and the numbers of receptors. Many nonpharmacologic comfort measures are thought to work by increasing the release of endorphins. If IV fluids and continuous electronic fetal monitoring are required during labor, asking if it is possible to sit or stand next to the bed will give the laboring woman more positions with which to work. If telemetry is available, the laboring woman can walk and change positions, taking the IV pole with her. Having a doula to provide support and encouragement to both the laboring woman and her labor partner will enhance progress and comfort. Finally, placing the baby skin-to-skin on the mother's chest immediately after birth and leaving the baby there until the first feed is accomplished even in the event of a cesarean will increase substantially levels of oxytocin, endorphins, and prolactin. Keeping mother and baby together after the birth with skin-to-skin contact and frequent breastfeeding will help to compensate for the interference from synthetic oxytocin and other medical interventions and will increase levels of the critical birth hormones to promote successful breastfeeding and attachment.

What Can Childbirth Educators Do to Encourage Women to Let Labor Begin on Its Own?

Several years ago, physicians and childbirth educators in a large midwestern hospital argued about who was responsible for the recent increase in the number of inductions. The physicians said, “Our patients are demanding to be induced. We are just giving them what they want.” The childbirth educators retorted, “The students in our classes tell us that it is the doctors who are suggesting induction” (Personal communication). To help resolve the argument, the doctors helped to fund a randomized, controlled trial to look at whether childbirth education could decrease the number of inductions. First, researchers looked at induction rates for women who attended childbirth classes at the hospital versus women who did not attend class. The induction rates were similar in both groups. Then the researchers created a special 45-minute presentation on the risks of labor induction, titled, “Is Labor Induction Right for You?” After several months of offering childbirth education classes with the added presentation, researchers again looked at the induction rates between those who attended classes and those who did not. This time, those who attended classes were significantly less likely to have their labors induced (Simpson, Newman, & Chirino, 2010a; Simpson, Newman, & Chirino, 2010b).

Although ACOG is now supporting the option of elective induction for low-risk women at 39 weeks, the study described above demonstrates that childbirth education can influence decision-making by childbearing families.

What Can You Do in Your Childbirth Classes?

Encourage students to think of a range for their due dates, rather than a specific day. Share the information from Dr. Buckley's report, The Hormonal Physiology of Childbearing, so that your students understand the importance of having optimal levels of birth hormones “on board” for labor and birth, breastfeeding, and attachment. Describe the important growth and development that takes place in the baby's brain and lungs in the last weeks and days of pregnancy. Show them the March of Dimes poster or card illustrating brain growth in the last weeks of pregnancy (March of Dimes, 2006). Encourage students to think about the type of birth they would like to have. The woman who is planning for an early epidural may not mind the interventions that are required for most inductions. However, the woman who hopes to labor out of bed and use a variety of nonpharmacologic comfort strategies needs to understand the interventions that are required with labor induction. Describe the cascade of interventions that begins with induction. Do a mock induction in which you have a student pretend to be induced; use props to attach the IV bag, fetal monitor belts, epidural analgesia, and urinary catheter. Prepare students for the possibility of labor lasting 42 hours or longer with elective induction. Have students role-play making decisions about possible induction for a variety of reasons and encourage group discussion. Share positive stories and images of normal pregnancy, physiologic labor and birth, and breastfeeding so that students have confidence in their own body's innate ability to give birth. Encourage women to trust that their bodies know the perfect birth date for their babies.

CONCLUSION

In the classic summary of Cochrane Reviews on maternity care published in 2000, A Guide to Effective Care in Pregnancy and Childbirth (Enkin, Keirse, & Neilson, 2000), the authors identified this principle for evaluating care:

Any interference with the natural process of pregnancy and childbirth should also be shown to do more good than harm (Enkin et al., 2000, p. 486).

For many in the birth world, the small reduction in cesarean rates seen in the ARRIVE trial does not justify the interference into the natural process of pregnancy and labor and birth that is caused by labor induction.

Lamaze childbirth educators should continue to promote the first Healthy Birth Practice, Let Labor Begin on Its Own. Providing full and accurate information and allowing time for thoughtful discussion will help childbearing families make informed decisions and plan for the birth that they hope to have.

Biography

DEBBY AMIS is the coauthor of Prepared Childbirth — The Family Way, Prepared Childbirth — The Educator's Guide, and the 2012 and 2015 editions of The Lamaze Toolkit. She is also a trainer for the New York City Lamaze Childbirth Educator program. She and her husband live in Houston, Texas.

DISCLOSURE

The authors have no relevant financial interest or affiliations with any commercial interests related to the subjects discussed within this article.