ACOG/SMFM Consensus Advance... · 2014. 4. 9. · ACOG/SMFM OBSTETRIC CARE CONSENSUS Safe...

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ACOG/SMFM OBSTETRIC CARE CONSENSUS

Safe prevention of the primarycesarean delivery
This document was developed jointly by the American College of Obstetricians and Gynecologists (the College) and theSociety for MaternaleFetal Medicine with the assistance of Aaron B. Caughey, MD, PhD; Alison G. Cahill, MD, MSCI;Jeanne-Marie Guise, MD, MPH; and Dwight J. Rouse, MD, MSPH
The information reflects emerging clinical and scientific advances as of the date issued, is subject to change, and should not be construed as dictating

an exclusive course of treatment or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and

limitations unique to the institution or type of practice.

In 2011, 1 in 3 women who gave birth in the United States did so by cesarean delivery.Cesarean birth can be lifesaving for the fetus, the mother, or both in certain cases.However, the rapid increase in cesarean birth rates from 1996 through 2011 withoutclear evidence of concomitant decreases in maternal or neonatal morbidity or mortalityraises significant concern that cesarean delivery is overused. Variation in the rates ofnulliparous, term, singleton, vertex cesarean births also indicates that clinical practicepatterns affect the number of cesarean births performed. The most common indicationsfor primary cesarean delivery include, in order of frequency, labor dystocia, abnormal orindeterminate (formerly, nonreassuring) fetal heart rate tracing, fetal malpresentation,multiple gestation, and suspected fetal macrosomia. Safe reduction of the rate of pri-mary cesarean deliveries will require different approaches for each of these, as well asother, indications. For example, it may be necessary to revisit the definition of labordystocia because recent data show that contemporary labor progresses at a ratesubstantially slower than what was historically taught. Additionally, improved andstandardized fetal heart rate interpretation and management may have an effect.Increasing women’s access to nonmedical interventions during labor, such as con-tinuous labor and delivery support, also has been shown to reduce cesarean birth rates.External cephalic version for breech presentation and a trial of labor for women with twingestations when the first twin is in cephalic presentation are other of several examplesof interventions that can contribute to the safe lowering of the primary cesareandelivery rate.

BackgroundIn 2011, 1 in 3 women who gave birthin the United States did so by cesareandelivery.1 Even though the rates of pri-mary and total cesarean delivery haveplateaued recently, there was a rapidincrease in cesarean rates from 1996through 2011 (Figure 1). Although ce-sarean delivery can be lifesaving for thefetus, the mother, or both in certaincases, the rapid increase in the rateof cesarean births without evidence ofconcomitant decreases in maternal orneonatal morbidity or mortality raisessignificant concern that cesarean de-livery is overused.2 Therefore, it isimportant for health care providers tounderstand the short-term and long-term tradeoffs between cesarean andvaginal delivery, as well as the safe andappropriate opportunities to preventoveruse of cesarean delivery, particularlyprimary cesarean delivery.

Balancing risks and benefitsChildbirth by its very nature carries po-tential risks for the woman and her baby,regardless of the route of delivery.The National Institutes of Health hascommissioned evidence-based reportsover recent years to examine the risksand benefits of cesarean and vaginaldelivery3 (Table 1). For certain clinical

The authors report no conflict of interest.

This article is being published concurrently in theMarch 2014 issue of Obstetrics & Gynecology(Obstet Gynecol 2014;123:693-711).

http://dx.doi.org/10.1016/j.ajog.2014.01.026

conditionsesuch as placenta previa oruterine ruptureecesarean delivery isfirmly established as the safest route ofdelivery. However, for most pregnancies,which are low-risk, cesarean deliveryappears to pose greater risk of maternalmorbidity and mortality than vaginaldelivery4 (Table 1).It is difficult to isolate the morbidity

caused specifically by route of delivery.For example, in one of the few ran-domized trials of approach to delivery,women with a breech presentationwere randomized to undergo plannedcesarean delivery or planned vaginal

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delivery, although there was crossover inboth treatment arms.5 In this study, at3-month follow-up, women were morelikely to have urinary, but not fecal, in-continence if they had been randomizedto the planned vaginal delivery group.However, this difference was no longersignificant at 2-year follow-up.6 Becauseof the size of this randomized trial, it wasnot powered to look at other measures ofmaternal morbidity.

A large population-based study fromCanada found that the risk of severematernal morbiditiesedefined as hem-orrhage that requires hysterectomy or

erican Journal of Obstetrics & Gynecology 179

http://dx.doi.org/10.1016/j.ajog.2014.01.026

FIGURE 1US delivery rates, 1989 through 2011

CD, cesarean delivery; VBAC, vaginal birth after cesarean delivery.

*Percent of women who have VBAC; yRate based on total number of deliveries.Data from National Vital Statistics and from Martin et al.77

ACOG. Safe prevention of primary cesarean delivery. Am J Obstet Gynecol 2014.


transfusion, uterine rupture, anestheticcomplications, shock, cardiac arrest,acute renal failure, assisted ventilation,venous thromboembolism, major infec-tion, or in-hospital wound disruptionor hematomaewas increased 3-foldfor cesarean delivery as compared withvaginal delivery (2.7% vs 0.9%, respec-tively).7 There also are concerns regard-ing the long-term risks associated withcesarean delivery, particularly thoseassociated with subsequent pregnancies.The incidence of placental abnormal-ities, such as placenta previa, in futurepregnancies increases with each subse-quent cesarean delivery, from 1% with1 prior cesarean delivery to almost 3%with �3 prior cesarean deliveries. Inaddition, an increasing number of priorcesareans is associated with the mor-bidity of placental previa: after 3 cesareandeliveries, the risk that a placenta previawill be complicated by placenta accreta is

180 American Journal of Obstetrics & Gynecology

nearly 40%.8 This combination of com-plications not only significantly increasesmaternal morbidity but also increasesthe risk of adverse neonatal outcomes,such as neonatal intensive care unitadmission and perinatal death.3,9,10

Thus, although the initial cesarean de-livery is associated with some increasesin morbidity and mortality, the down-stream effects are even greater because ofthe risks from repeat cesareans in futurepregnancies.11

Indications for primary cesareanThere is great regional variation by statein the rate of total cesarean deliveryacross the United States, ranging froma low of 23% to a high of nearly 40%(Figure 2). Variation in the rates ofnulliparous term singleton vertexcesarean births indicates that clinicalpractice patterns affect the number ofcesarean births performed. There also is

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substantial hospital-level variation.Studies have shown a 10-fold variationin the cesarean delivery rate across hos-pitals in the United States, from 7.1-69.9%, and a 15-fold variation amonglow-risk women, from 2.4-36.5%.12

Studies that have evaluated the roleof maternal characteristics, such asage, weight, and ethnicity, have con-sistently found these factors do notaccount fully for the temporal increasein the cesarean delivery rate or itsregional variations.13-15 These findingssuggest that other potentially modifiablefactors, such as patient preferences andpractice variation among hospitals, sys-tems, and health care providers, likelycontribute to the escalating cesareandelivery rates.

To understand the degree to whichcesarean deliveries may be preventable, itis important to know why cesareans areperformed. In a 2011 population-basedstudy, the most common indications forprimary cesarean delivery included, inorder of frequency, labor dystocia,abnormal or indeterminate (formerly,nonreassuring) fetal heart rate tracing,fetal malpresentation, multiple ges-tation, and suspected fetal macrosomia(Figure 3).16 Arrest of labor and abnor-mal or indeterminate fetal heart ratetracing accounted for more than half ofall primary cesarean deliveries in thestudy population. Safe reduction of therate of primary cesarean deliveries willrequire different approaches for eachof these indications. For example, it maybe necessary to revisit the definition oflabor dystocia because recent data showthat contemporary labor progresses ata rate substantially slower than what hasbeen historically taught. Improved andstandardized fetal heart rate inter-pretation and management also mayhave an effect. Increasing women’s accessto nonmedical interventions during la-bor, such as continuous labor support,also has been shown to reduce cesareanbirth rates. External cephalic versionfor breech presentation and a trial oflabor for women with twin gestationswhen the first twin is in cephalicpresentation also can contribute to thesafe lowering of the primary cesareandelivery rate.

TABLE 1Risk of adverse maternal and neonatal outcomes by mode of delivery

Outcome

Risk

Vaginal delivery Cesarean delivery

Maternal

Overall severe morbidityand mortalitya

8.6%0.9%

9.2%a

2.7%

Maternal mortalityb 3.6:100,000 13.3:100,000

Amniotic fluid embolismc 3.3-7.7:100,000 15.8:100,000

Third- or fourth-degreeperineal laceration117

1.0-3.0% NA (scheduled delivery)

Placental abnormalitiesd Increased with prior cesarean vs vaginal delivery, andrisk continues to increase with each subsequentcesarean delivery

Urinary incontinence6 No difference between cesarean and vaginal delivery at 2 y

Postpartum depression117 No difference between cesarean and vaginal delivery

Neonatal

Laceration2 NA 1.0-2.0%

Respiratory morbidity2 <1.0% 1.0-4.0% (without labor)

Shoulder dystocia 1.0-2.0% 0%

NA, not available.

a Defined as �1 of following: death, postpartum bleeding, genital tract injury; wound disruption, wound infection, or both;systemic infection; b Defined as any 1 of following: death, hemorrhage requiring hysterectomy or transfusion; uterine rupture;anesthetic complications; shock; cardiac arrest; acute renal failure; assisted ventilation venous thromboembolic event; majorinfection; in-hospital wound disruption, wound hematoma, or both. Data from Liu et al7; c Data from Deneux-Tharaux Cet al115; d Data from Abenhaim et al116; e Data from Silver et al.8


FIGURE 2US total cesarean delivery rates by state, 2010

Data from Martin et al.77


www.AJOG.org ACOG/SMFM Consensus

CLINICAL MANAGEMENT Q&A

What is the appropriate definition ofabnormally progressing first-stagelabor?

Definition of abnormalfirst-stage laborThe first stage of labor has been histor-ically divided into the latent phase andthe active phase based on the work byFriedman in the 1950s and beyond.The latent phase of labor is defined asbeginning with maternal perception ofregular contractions.17 On the basis ofthe 95th percentile threshold, histori-cally, the latent phase has been defined asprolonged when it is >20 hours in nul-liparous women and >14 hours inmultiparous women.18 The active phaseof labor has been defined as the point atwhich the rate of change of cervicaldilation significantly increases.

Active-phase labor abnormalities canbe categorized either as protraction dis-orders (slower progress than normal) orarrest disorders (complete cessation ofprogress). Based on Friedman’s work, thetraditional definition of a protractedactive phase (based on the 95th percen-tile) has been cervical dilatation in theactive phase of<1.2 cm/h for nulliparouswomen and <1.5 cm/h for multiparouswomen.19 Active-phase arrest tradition-ally has been defined as the absence ofcervical change for �2 hours in thepresence of adequate uterine contractionsand cervical dilation of at least 4 cm.

However, more recent data from theConsortium on Safe Labor have beenused to revise the definition of con-temporary normal labor progress.20 Inthis retrospective study conducted at 19US hospitals, the duration of labor wasanalyzed in 62,415 parturient women,each of whom delivered a singleton ver-tex fetus vaginally and had a normalperinatal outcome. In this study, the95th percentile rate of active-phasedilation was substantially slower thanthe standard rate derived from Fried-man’s work, varying from 0.5e0.7 cm/hfor nulliparous women and from0.5e1.3 cm/h for multiparous women(the ranges reflect that at more advanced

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FIGURE 3Indications for primary cesarean delivery

Data from Barber et al.16



dilation, labor proceeded more quickly)(Table 2).

The Consortium on Safe Labor datahighlight 2 important features of con-temporary labor progress (Figure 4).

TABLE 2Spontaneous labor progress stratifie

Cervical dilation, cm

Median elapsed tim

Parity 0(95th percentile)

3-4 1.8 (8.1)

4-5 1.3 (6.4)

5-6 0.8 (3.2)

6-7 0.6 (2.2)

7-8 0.5 (1.6)

8-9 0.5 (1.4)

9-10 0.5 (1.8)

Modified from Zhang et al.20

ACOG. Safe prevention of primary cesarean delivery. Am J


First, from 4-6 cm, nulliparous andmultiparous women dilated at essentiallythe same rate, and more slowly than his-torically described. Beyond 6 cm, multi-parous women dilated more rapidly.

d by cervical dilation and parity

e, h

Parity 1(95th percentile)

Parity ‡2(95th percentile)

e e

1.4 (7.3) 1.4 (7.0)

0.8 (3.4) 0.8 (3.4)

0.5 (1.9) 0.5 (1.8)

0.4 (1.3) 0.4 (1.2)

0.3 (1.0) 0.3 (0.9)

0.3 (0.9) 0.3 (0.8)

Obstet Gynecol 2014.

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Second, the maximal slope in the rateof change of cervical dilation over time(ie, the active phase) often did not startuntil at least 6 cm. The Consortium onSafe Labor data do not directly addressan optimal duration for the diagnosis ofactive-phase protraction or labor arrest,but do suggest that neither should bediagnosed <6 cm of dilation. Becausethey are contemporary and robust, itseems that the Consortium on Safe Labordata, rather than the standards proposedby Friedman, should inform evidence-based labor management.

How should abnormally progressingfirst-stage labor be managed?

Management of abnormalfirst-stage laborAlthough labor management strategiespredicated on the recent Consortium onSafe Labor information have not beenassessed yet, some insight into howmanagement of abnormal first-stage la-bor might be optimized can be deducedfrom prior studies.

The definitions of a prolonged latentphase are still based on data from Fried-man and modern investigators have notparticularly focused on the latent phaseof labor. Most women with a prolongedlatent phase ultimately will enter theactive phase with expectant management.With few exceptions, the remainder eitherwill cease contracting or, with amniotomyor oxytocin (or both), achieve the activephase.18 Thus, a prolonged latent phase(eg,>20hours in nulliparouswomen and>14 hours in multiparous women)should not be an indication for cesareandelivery (Table 3 and Appendix).

When the first stage of labor is pro-tracted or arrested, oxytocin is commonlyrecommended. Several studies have eval-uated the optimal duration of oxytocinaugmentation in the face of labor pro-traction or arrest. A prospective study ofthe progress of labor in 220 nulliparouswomen and 99 multiparous women whospontaneously entered labor evaluated thebenefit of prolonging oxytocin augmen-tation for an additional 4 hours (for a totalof 8 hours) in patients whowere dilated atleast 3 cm and had unsatisfactory progress(either protraction or arrest) after an

TABLE 3Recommendations for safe prevention of primary cesarean delivery

Recommendations Grade of recommendations

First stage of labor

A prolonged latent phase (eg, >20 h in nulliparouswomen and >14 h in multiparous women) should not beindication for cesarean delivery.

1BStrong recommendation,moderate-quality evidence

Slow but progressive labor in first stage of labor shouldnot be indication for cesarean delivery.


Cervical dilation of 6 cm should be considered thresholdfor active phase of most women in labor. Thus, before6 cm of dilation is achieved, standards of active-phaseprogress should not be applied.


Cesarean delivery for active-phase arrest in first stage oflabor should be reserved for women �6 cm of dilationwith ruptured membranes who fail to progress despite 4 hof adequate uterine activity, or at least 6 h of oxytocinadministration with inadequate uterine activity and nocervical change.


Second stage of labor

A specific absolute maximum length of time spentin second stage of labor beyond which all womenshould undergo operative delivery has not beenidentified.

1CStrong recommendation,low-quality evidence

Before diagnosing arrest of labor in second stage, ifmaternal and fetal conditions permit, allow for following:� At least 2 h of pushing in multiparous women (1B)� At least 3 h of pushing in nulliparous women (1B)Longer durations may be appropriate on individualizedbasis (eg, with use of epidural analgesia or withfetal malposition) as long as progress is beingdocumented. (1B)


Operative vaginal delivery in second stage of labor byexperienced and well-trained physicians should beconsidered safe, acceptable alternative to cesareandelivery. Training in, and ongoing maintenance of,practical skills related to operative vaginal delivery shouldbe encouraged.


Manual rotation of fetal occiput in setting of fetalmalposition in second stage of labor is reasonableintervention to consider before moving to operativevaginal delivery or cesarean delivery. To safely preventcesarean deliveries in setting of malposition, it isimportant to assess fetal position in second stage of labor,particularly in setting of abnormal fetal descent.


Fetal heart rate monitoring

Amnioinfusion for repetitive variable fetal heart ratedecelerations may safely reduce rate of cesareandelivery.

1AStrong recommendation,high-quality evidence

Scalp stimulation can be used asmeans of assessing fetalacid-base status when abnormal or indeterminate(formerly, nonreassuring) fetal heart patterns (eg, minimalvariability) are present and is safe alternative to cesareandelivery in this setting.


ACOG. Safe prevention of primary cesarean delivery. Am J Obstet Gynecol 2014. (continued)


initial 4-hour augmentation period.21

The researchers found that of womenwho received at least 4 additional hours ofoxytocin, 38% delivered vaginally, andnone had neonates with 5-minute Apgarscores of <6. In nulliparous women,a period of 8 hours of augmentationresulted in an 18% cesarean delivery rateand no cases of birth injury or asphyxia,whereas if the period of augmentationhad been limited to 4 hours, the cesareandelivery rate would have been twice ashigh given the number of women whohad not made significant progress at 4hours. Thus, slow but progressive labor inthe first stage of labor should not be anindication for cesarean delivery (Table 3).

A study of >500 women found thatextending the minimum period of oxy-tocin augmentation for active-phase ar-rest from 2 hours to at least 4 hoursallowed the majority of women who hadnot progressed at the 2-hour mark togive birth vaginally without adverselyaffecting neonatal outcome.22 The re-searchers defined active-phase laborarrest as �1 cm of labor progress over2 hours in women who entered laborspontaneously and were at least 4 cmdilated at the time arrest was diagnosed.The vaginal delivery rate for womenwhohad not progressed despite 2 hours ofoxytocin augmentation was 91% formultiparous women and 74% for nulli-parous women. For womenwho had notprogressed despite 4 hours of oxytocin(and in whom oxytocin was continued atthe judgment of the health care pro-vider), the vaginal delivery rates were88% in multiparous women and 56% innulliparous women. Subsequently, theresearchers validated these results ina different cohort of 501 prospectivelytreated women.23 An additional study of1014 women conducted by differentauthors demonstrated that using thesame criteria in women with spontane-ous labor or induced labor would leadto a significantly higher proportionof women achieving vaginal deliverywith no increase in neonatal complica-tions.24 Of note, prolonged first stage oflabor has been associated with anincreased risk of chorioamnionitis in thestudies listed, but whether this relation-ship is causal is unclear (ie, evolving


TABLE 3Recommendations for safe prevention of primary cesarean delivery(continued)

Recommendations Grade of recommendations

Induction of labor

Before 41 0/7 wks of gestation, induction of laborgenerally should be performed based on maternal andfetal medical indications. Inductions at �41 0/7 wks ofgestation should be performed to reduce risk of cesareandelivery and risk of perinatal morbidity and mortality.

1AStrong recommendation,high-quality evidence

Cervical ripening methods should be used when labor isinduced in women with unfavorable cervix.


If maternal and fetal status allow, cesarean deliveries forfailed induction of labor in latent phase can be avoided byallowing longer durations of latent phase (up to�24 h) andrequiring that oxytocin be administered for at least 12-18 hafter membrane rupture before deeming induction failure.


Fetal malpresentation

Fetal presentation should be assessed and documentedbeginning at 36 0/7 wks of gestation to allow for externalcephalic version to be offered.


Suspected fetal macrosomia

Cesarean delivery to avoid potential birth trauma shouldbe limited to estimated fetal weights of at least 5000 g inwomen without diabetes and at least 4500 g in womenwith diabetes. Prevalence of birth weight of �5000 g israre, and patients should be counseled that estimates offetal weight, particularly late in gestation, are imprecise.

2CWeak recommendation,low-quality evidence

Excessive maternal weight gain

Women should be counseled about IOM maternal weightguidelines in attempt to avoid excessive weight gain.


Twin gestations

Perinatal outcomes for twin gestations in which first twinis in cephalic presentation are not improved by cesareandelivery. Thus, women with either cephalic/cephalic-presenting twins or cephalic/noncephalic presentingtwins should be counseled to attempt vaginal delivery.


Other

Individuals, organizations, and governing bodies shouldwork to ensure that research is conducted to providebetter knowledge base to guide decisions regardingcesarean delivery and to encourage policy changes thatsafely lower rate of primary cesarean delivery.


IOM, Institute of Medicine.



chorioamnionitis may predispose tolonger labors). Thus, although this rela-tionship needs further elucidation, nei-ther chorioamnionitis nor its durationshould be an indication for cesareandelivery.25


Given these data, as long as fetal andmaternal status are reassuring, cervicaldilation of 6 cm should be considered thethreshold for the active phase of mostwomen in labor (Box). Thus, before6 cm of dilation is achieved, standards

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of active-phase progress should not beapplied (Table 3). Further, cesarean de-livery for active-phase arrest in the firststage of labor should be reserved forwomen�6 cm of dilation with rupturedmembranes who fail to progress despite4 hours of adequate uterine activity, or atleast 6 hours of oxytocin administrationwith inadequate uterine activity and nocervical change (Table 3).22

What is the appropriate definition ofabnormal second-stage labor?

The second stage of labor begins when thecervix becomes fully dilated and endswithdelivery of the neonate. Parity, delayedpushing, use of epidural analgesia,maternal body mass index, birth weight,occiput posterior position, and fetal sta-tion at complete dilation all have beenshown to affect the length of the secondstage of labor.26 Further, it is important toconsider not just the mean or medianduration of the second stage of labor butalso the 95th percentile duration. In theConsortium on Safe Labor study dis-cussed earlier, although the mean andmedian duration of the second stage dif-fered by 30 minutes, the 95th percentilethreshold was approximately 1 hour lon-ger in women who received epiduralanalgesia than in those who did not.20

Defining what constitutes an appro-priate duration of the second stage is notstraightforward because it involvesa consideration of multiple short-termand long-term maternal and neonataloutcomesesome of them competing.Multiple investigators have examined therelationship between the duration of thesecond stage of labor and adversematernal and neonatal outcomes in anattempt to define what should constitutea “normal” duration of the second stage.In the era of electronic fetal monitoring,among neonates born to nulliparouswomen, adverse neonatal outcomesgenerally have not been associated withthe duration of the second stage of labor.In a secondary analysis of a multicenterrandomized study of fetal pulse oxime-try, of 4126 nulliparous women whoreached the second stage of labor, noneof the following neonatal outcomes wasfound to be related to the duration of the

DEFINITION OF ARREST OF LABOR INFIRST STAGESpontaneous labor: �6 cm dilation withmembrane rupture and 1 of following:�4 h of adequate contractions (eg,>200Montevideo units); �6 h of inadequatecontractions and no cervical change.

FIGURE 4Average labor curves by parity in singleton term pregnancieswith spontaneous onset of labor, vaginal delivery, andnormal neonatal outcomes

P0, nulliparous women; P1, women of parity 1; P2+, women of parity �2.

Modified from Zhang et al.20



second stage, which in some cases was�5hours: 5-minute Apgar score of <4, um-bilical artery pH <7.0, intubation in thedelivery room, need for admission to theneonatal intensive care unit, or neonatalsepsis.27 Similarly, in a secondary analysisof 1862 women enrolled in an early vsdelayed pushing trial, a longer durationof active pushing was not associatedwith adverse neonatal outcomes, even inwomenwho pushed for>3 hours.28 Thisalso was found in a large, retrospectivecohort study of 15,759 nulliparouswomen even in a group of women whosesecond stage progressed >4 hours.29

The duration of the second stage oflabor and its relationship to neonataloutcomes has been less extensivelystudied in multiparous women. In 1retrospective study of 5158 multiparouswomen, when the duration of the secondstage of labor was >3 hours, the risk ofa 5-minute Apgar score of<7, admissionto the neonatal intensive care unit, anda composite of neonatal morbidity wereall significantly increased.30 A popula-tion-based study of 58,113 multiparouswomen yielded similar results when theduration of the second stage was >2hours.31

A longer duration of the second stageof labor is associated with adversematernal outcomes, such as higher ratesof puerperal infection, third-degree andfourth-degree perineal lacerations, andpostpartum hemorrhage.27 Moreover,for each hour of the second stage, thechance for spontaneous vaginal deliverydecreases progressively. Researchers havefound that after a �3-hour second stageof labor, only 1 in 4 nulliparous women27

and 1 in 3 multiparous women give birthspontaneously, whereas up to 30-50%may require operative delivery to givebirth vaginally in the current secondstage of labor threshold environment.30

Thus, the literature supports that forwomen, longer time in the second stageof labor is associated with increased risksof morbidity and a decreasing probabil-ity of spontaneous vaginal delivery.However, this risk increase may not beentirely related to the duration of thesecond stage per se, but rather to healthcare provider actions and interventionsin response to it (eg, operative delivery

and the associated risks of perinealtrauma).32 With appropriate monitor-ing, however, the absolute risks ofadverse fetal and neonatal consequencesof increasing second-stage durationappear to be, at worst, low and incre-mental. For example, in the study of58,113 multiparous women cited earlier,although the risk of a 5-minute Apgarscore of <7 and birth depression wasincreased when the second stage of laborlasted>2 hours, the absolute risk of theseoutcomes was low (<1.5%) with dura-tions<2 hours andwas not doubled evenwith durations >5 hours. Moreover, theduration of the second stage of labor wasunrelated to the risk of neonatal sepsis ormajor trauma. Thus, a specific absolutemaximum length of time spent in thesecond stage of labor beyond which allwomen should undergo operative de-livery has not been identified (Table 3).Similar to the first stage of labor, a pro-longed second stage of labor has beenassociated with an increased risk ofchorioamnionitis in the studies listed,but whether this relationship is causalis unclear (ie, evolving chorioamnio-nitis may predispose to longer labors).Again, neither chorioamnionitis nor its

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duration should be an indication forcesarean delivery.

How should abnormally progressingsecond-stage labor be managed?

Given the available literature, beforediagnosing arrest of labor in the secondstage and if the maternal and fetal con-ditions permit, at least 2 hours of push-ing in multiparous women and at least3 hours of pushing in nulliparouswomen should be allowed (Table 3).Longer durations may be appropriate onan individualized basis (eg, with theuse of epidural analgesia or with fetalmalposition) as long as progress is beingdocumented (Table 3). For example,the recent Eunice Kennedy ShriverNational Institute of Child Healthand Human Development document



suggested allowing 1 additional hour inthe setting of an epidural, thus, at least3 hours in multiparous women and4 hours in nulliparous women be used todiagnose second-stage arrest, althoughthat document did not clarify betweenpushing time or total second stage.33

What other management approachesmay reduce cesarean deliveries in thesecond stage of labor?

In addition to greater expectant manage-ment of the second stage, 2 other prac-tices could potentially reduce cesareandeliveries in the second stage: (1) operativevaginal delivery; and (2) manual rotationof the fetal occiput for malposition.

Operative vaginal deliveryIn contrast with the increasing rate ofcesarean delivery, the rates of operativevaginal deliveries (via either vacuumor forceps) have decreased significantlyduring the past 15 years.34 Yet, compar-ison of the outcomes of operative vaginaldeliveries and unplanned cesarean de-liveries shows no difference in seriousneonatal morbidity (eg, intracerebralhemorrhage or death). In a large, retro-spective cohort study, the rate of intra-cranial hemorrhage associated withvacuum extraction did not differ sig-nificantly from that associated witheither forceps delivery (odds ratio [OR],1.2; 95% confidence interval [CI],0.7e2.2) or cesarean delivery (OR, 0.9;95% CI, 0.6e1.4).35 In a more recentstudy, forceps-assisted vaginal deliverieswere associated with a reduced risk of thecombined outcome of seizure, intra-ventricular hemorrhage, or subduralhemorrhage as compared with eithervacuum-assisted vaginal delivery (OR,0.60; 95% CI, 0.40e0.90) or cesareandelivery (OR, 0.68; 95% CI, 0.48e0.97),with no significant difference betweenvacuum delivery or cesarean delivery.36

Fewer than 3% of women in whoman operative vaginal delivery has beenattempted go on to deliver by cesar-ean.37 Although attempts at operativevaginal delivery from a midpelvic sta-tion (0 and +1 on thee5 to +5 scale) orfrom an occiput transverse or occiputposterior position with rotation are


reasonable in selected cases,38 theseprocedures require a higher level of skilland are more likely to fail than low(�+2) or outlet (scalp visible at theintroitus) operative deliveries. Per-forming low or outlet procedures infetuses not believed to be macrosomicis likely to safely reduce the risk of ce-sarean delivery in the second stage oflabor. However, the number of healthcare providers who are adequatelytrained to perform forceps and vacuumdeliveries is decreasing. In one survey,most (55%) resident physicians intraining did not feel competent to per-form a forceps delivery upon com-pletion of residency.39 Thus, trainingresident physicians in the performanceof operative vaginal deliveries and usingsimulation for retraining and ongoingmaintenance of practice would likelycontribute to a safe lowering of the ce-sarean delivery rate.40 In sum, operativevaginal delivery in the second stage oflabor by experienced and well-trainedphysicians should be considered a safe,acceptable alternative to cesarean de-livery. Training in, and ongoing main-tenance of, practical skills related tooperative vaginal delivery should beencouraged (Table 3).

Manual rotation of the fetal occiputOcciput posterior and occiput transversepositions are associated with an increasein cesarean delivery and neonatal com-plications.41,42 Historically, forceps rota-tion of the fetal occiput from occiputposterior or occiput transverse wascommon practice. Today this procedure,although still considered a reasonablemanagement approach, has fallen out offavor and is rarely taught in the UnitedStates. An alternative approach is manualrotation of the fetal occiput, which hasbeen associated with a safe reduction inthe risk of cesarean delivery and is sup-ported by the Society of Obstetriciansand Gynaecologists of Canada.43-45 Forexample, in a small prospective trial of 61women, those who were offered a trial ofmanual rotation experienced a lower rateof cesarean delivery (0%) compared withthose treated without manual rotation(23%, P ¼ .001).46 A large, retrospectivecohort study found a similar large

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reduction in cesarean delivery (9% vs41%, P< .001) associated with the use ofmanual rotation.43 Of the 731 women inthis study who underwent manual rota-tion, none experienced an umbilical cordprolapse. Further, there was no differencein either birth trauma or neonatal acid-emia between neonates who had experi-enced an attempt at manual rotation vsthose who had not.43 To consider anintervention for a fetal malposition, theproper assessment of fetal position mustbe made. Intrapartum ultrasonographyhas been used to increase the accuratediagnosis of fetal position when the dig-ital examination results are uncertain.47

Given these data, which are limitedfor safety and efficacy, manual rotationof the fetal occiput in the setting offetal malposition in the second stage oflabor is a reasonable intervention toconsider before moving to operativevaginal delivery or cesarean delivery.To safely prevent cesarean deliveriesin the setting of malposition, it isimportant to assess the fetal position inthe second stage of labor, particularlyin the setting of abnormal fetal descent(Table 3).

Which fetal heart tracings deserveintervention, and what are theseinterventions?

The second most common indicationfor primary cesarean is an abnormal orindeterminate fetal heart rate tracing(Figure 3). Given the known variation ininterpretation and management of fetalheart rate tracings, a standardizedapproach is a logical potential goal forinterventions to safely reduce the cesar-ean delivery rate.

Category III fetal heart rate tracingsare abnormal and require intervention.48

The elements of category III patternsewhich include either absent fetalheart rate variability with recurrent latedecelerations, recurrent variable de-celerations, or bradycardia; or a sinusoi-dal rhythmehave been associated withabnormal neonatal arterial umbilicalcord pH, encephalopathy, and cerebralpalsy.49-52 Intrauterine resuscitativeeffortseincluding maternal reposition-ing and oxygen supplementation,


assessment for hypotension and tachy-systole that may be corrected, and eval-uation for other causes, such as umbilicalcord prolapseeshould be performedexpeditiously; however, when such ef-forts do not quickly resolve the categoryIII tracing, delivery as rapidly and assafely possible is indicated. The Ameri-can Congress of Obstetricians andGynecologists (ACOG) recommendspreparations for imminent delivery inthe event that intrauterine resuscitativemeasures do not improve the fetal heartrate pattern.48

In contrast, category I fetal hearttracings are normal and do not requireintervention other than ongoing assess-ment with continuous or intermittentmonitoring, given that patterns canchange over time. Moderate variabilityand the presence of accelerations, whichare features of category I patterns, haveproved to be reliable indicators of nor-mal neonatal umbilical cord arterial pH(�7.20).53,54

Most intrapartum fetal heart ratetracings are category II.50,55 Category IItracings are indeterminate and com-prise a diverse spectrum of fetal heartrate patterns that require evaluation,continued surveillance, initiation ofappropriate corrective measures whenindicated, and reevaluation.48 Basedon the high rate of first cesareandeliveries performed for the indicationof “nonreassuring fetal heart rate” (alsoknown as an “abnormal or indetermi-nate fetal heart rate”) and the rarityof category III patterns, it can bededuced that category II tracings likelyaccount for most cesarean deliveriesperformed for nonreassuring fetalstatus.16 Thus, one important consid-eration for health care providers whoare making the diagnosis of non-reassuring fetal status with the intent toproceed with cesarean delivery is toensure that clinically indicated mea-sures have been undertaken to resolvethe concerning elements of the cat-egory II tracing or provide reassuranceof fetal well-being.

Scalp stimulation to elicit fetal heartrate acceleration is an easily employedtool when the cervix is dilated and canoffer clinician reassurance that the fetus

is not acidotic. Spontaneous or elicitedheart rate accelerations are associatedwith a normal umbilical cord arterialpH (�7.20).54,56 Recurrent variable de-celerations, thought to be a physiologicresponse to repetitive compression ofthe umbilical cord, are not themselvespathologic. However, if frequent andpersistent, they can lead to fetal acidemiaover time. Conservative measures, suchas position change, may improve thispattern. Amnioinfusion with normalsaline also has been demonstrated toresolve variable fetal heart rate de-celerations57-59 and reduce the incidenceof cesarean delivery for a nonreassuringfetal heart rate pattern.59-61 Similarly,other elements of category II fetalheart rate tracings that may indicatefetal acidemia, such as minimal varia-bility or recurrent late decelerations,should be approached with in uteroresuscitation.48

Prolonged fetal heart rate de-celerations (which last >2 minutes but<10 minutes) often require inter-vention. They can occur after rapid cer-vical change or after hypotension (ie, inthe setting of regional analgesia). Pro-longed decelerations also may be a signof complications, such as abruptio pla-centae, umbilical cord prolapse, oruterine rupture; because of their poten-tial morbidity, these complicationsshould be considered in the differentialdiagnosis to allow for appropriate eval-uation and intervention.62-64 Uterinetachysystole, defined as >5 contractionsin 10 minutes averaged over 30 minutes,can occur spontaneously or because ofuterotonic agents (ie, oxytocin or pros-taglandins) and can be associated withfetal heart rate changes, such as pro-longed or late decelerations. Reductionor cessation of the contractile agent oradministration of a uterine relaxant,such as a beta-mimetic agent, can resolveuterine tachysystole and improve thefetal heart rate tracing.65 In contrast,there are no current data to support in-terventions specifically for decelerationswith “atypical features” (eg, shoulders,slow return to baseline, or variabilityonly within the deceleration) becausethey have not been associated with fetalacidemia.49,66

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There is not consistent evidence thatST-segment analysis and fetal pulse ox-imetry either improve outcomes orreduce cesarean delivery rates.67,68

Despite the evidence that fetal scalpsampling reduces the risk of cesareandelivery69,70 and the poor ability ofelectronic fetal heart rate monitoringpatterns to predict pH, intrapartum fetalscalp sampling has fallen out of favor inthe United States. This predominantly isdue to its invasive nature, the narrowclinical presentations for which it mightbe helpful, and the need for regulatorymeasures to maintain bedside testingavailability. Currently, this testing is notperformed in most US centers and a fetalblood sampling “kit” that is approved bythe US Food and Drug Administration isnot currently manufactured.

The unnecessary performance of ce-sarean deliveries for abnormal or inde-terminate fetal heart rate tracings can beattributed to limited knowledge aboutthe ability of the patterns to predictneonatal outcomes and the lack of rig-orous science to guide clinical responseto the patterns.55,71 Supplemental oxy-gen,72 intravenous fluid bolus,73 andtocolytic agents74 are routine compo-nents of intrauterine resuscitation75 thathave extremely limited data for effec-tiveness or safety. Performance of theseinterventions without a subsequentchange in fetal heart rate pattern is notnecessarily an indication for cesareandelivery. Medication exposure, regionalanalgesia, rapid labor progress, cervicalexamination, infection, maternal hypo-tension, and maternal fever all can affectthe fetal heart rate pattern.48 Attention tosuch factors will optimize clinical deci-sion making regarding the managementof abnormal or indeterminate fetalheart rate patterns and the need forcesarean delivery. Specifically, amnioin-fusion for repetitive variable fetal heartrate decelerations may safely reduce therate of cesarean delivery (Table 3). Scalpstimulation can be used as a means ofassessing fetal acid-base status whenabnormal or indeterminate (formerly,nonreassuring) fetal heart patterns (eg,minimal variability) are present and isa safe alternative to cesarean delivery inthis setting (Table 3).



What is the effect of induction oflabor on cesarean delivery?

The use of induction of labor hasincreased in the United States con-currently with the increase in the cesar-ean delivery rate, from 9.5% of births in1990 to 23.1% of births in 2008.76,77

Because women who undergo inductionof labor have higher rates of cesareandelivery than those who experiencespontaneous labor, it has been widelyassumed that induction of labor itselfincreases the risk of cesarean delivery.However, this assumption is predicatedon a faulty comparison of women whoare induced vs women in spontaneouslabor.78 Studies that compare inductionof labor to its actual alternative, expect-ant management awaiting spontaneouslabor, have found either no difference ora decreased risk of cesarean deliveryamong women who are induced.79-82

This appears to be true even for womenwith an unfavorable cervix.83

Available randomized trial data com-paring induction of labor vs expectantmanagement reinforce the more recentobservational data. For example, a met-aanalysis of prospective randomizedcontrolled trials conducted at <42 0/7weeks of gestation found that womenwho underwent induction of labor hada lower rate of cesarean delivery com-pared with those who received expectanttreatment.84 In addition, a metaanalysisof 3 older, small studies of induction oflabor <41 0/7 weeks of gestation alsodemonstrated a statistically significantreduction in the rate of cesarean de-livery.85 Additionally, increases in still-birth, neonatal death, and infant deathhave been associated with gestations at�41 0/7 weeks.86,87 In a 2012 Cochranemetaanalysis, induction of labor at �410/7 weeks of gestation was associatedwith a reduction in perinatal mortalitywhen compared with expectant man-agement.85 Therefore, at <41 0/7 weeksof gestation, induction of labor generallyshould be performed based on maternaland fetal medical indications. Inductionsat �41 0/7 weeks of gestation should beperformed to reduce the risk of cesareandelivery and the risk of perinatal mor-bidity and mortality (Table 3).


Once a decision has been made toproceed with a labor induction, varia-tions in the management of labor in-duction likely affect rates of cesareandelivery, particularly the use of cervicalripening agents for the unfavorable cer-vix and the lack of a standard definitionof what constitutes prolonged durationof the latent phase (a failed induction).Numerous studies have found that theuse of cervical ripening methodsesuchas misoprostol, dinoprostone, prosta-glandin E2 gel, Foley bulbs, and lami-naria tentselead to lower rates ofcesarean delivery than induction of laborwithout cervical ripening.69,88 The ben-efit is so widely accepted that recentstudies do not include a placebo ornonintervention group, but rathercompare one cervical ripening methodwith another.89 There also are data tosupport the use of >1 of these methodssequentially or in combination, such asmisoprostol and a Foley bulb, to facili-tate cervical ripening.90 Thus, cervicalripening methods should be used whenlabor is induced in women with an un-favorable cervix (Table 3).In the setting of induction of labor,

nonintervention in the latent phasewhen the fetal heart tracing is reassuringand maternal and fetal statuses are stableseems to reduce the risk of cesarean de-livery. Recent data indicate that the latentphase of labor is longer in induced laborcompared with spontaneous labor.91

Furthermore, at least 3 studies supportthat a substantial proportion of womenundergoing inductionwho remain in thelatent phase of labor for 12-18 hourswith oxytocin administration and rup-tured membranes will give birth vagi-nally if induction is continued.92-94 In 1study, 17% of women were still in thelatent phase of labor at >12 hours, and5% remained in the latent phase >18hours.93 In another study, of thosewomen who were in the latent phase for>12 hours and achieved active phase oflabor, the majority (60%) gave birthvaginally.94 Membrane rupture andoxytocin administration, except in rarecircumstances, should be consideredprerequisites to any definition of failedlabor induction, and experts have pro-posed waiting at least 24 hours in the

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setting of oxytocin and ruptured mem-branes before declaring an inductionfailed.33

Therefore, if the maternal and fetalstatus allow, cesarean deliveries for failedinduction of labor in the latent phase canbe avoided by allowing longer durationsof the latent phase (up to �24 hours)and requiring that oxytocin be admin-istered for at least 12-18 hours aftermembrane rupture before deeming theinduction a failure (Table 3).

What are the other indications forprimary cesarean delivery? Whatalternative management strategiescan be used for the safe prevention ofcesarean delivery in these cases?

Although labor arrest and abnormal orindeterminate fetal heart rate tracing arethe most common indications for pri-mary cesarean delivery, less commonindicationsesuch as fetal malpresenta-tion, suspected macrosomia, multiplegestation, and maternal infection (eg,herpes simplex virus)eaccount for tensof thousands of cesareans deliveries inthe United States annually. Safe preven-tion of primary cesarean deliveries willrequire different approaches for each ofthese indications.

Fetal malpresentationBreech presentation at �37 weeks ofgestation is estimated to complicate3.8% of pregnancies, and >85% ofpregnantwomenwith a persistent breechpresentation are delivered by cesarean.95

In one recent study, the rate of attemptedexternal cephalic version was 46% anddecreased during the study period.96

Thus, external cephalic version for fetalmalpresentation is likely underutilized,especially when considering that mostpatients with a successful external ce-phalic version will give birth vaginally.96

Obstetricians should offer and per-form external cephalic version when-ever possible.97 Furthermore, when anexternal cephalic version is planned,there is evidence that success may beenhanced by regional analgesia.98 Fetalpresentation should be assessed anddocumented beginning at 36 0/7 weeksof gestation to allow for external


cephalic version to be offered (Table 3).Before a vaginal breech delivery isplanned, women should be informedthat the risk of perinatal or neonatalmortality or short-term serious neo-natal morbidity may be higher than ifa cesarean delivery is planned, and thepatient’s informed consent should bedocumented.

Suspected fetal macrosomiaSuspected fetal macrosomia is not anindication for delivery and rarely is anindication for cesarean delivery. To avoidpotential birth trauma, ACOG recom-mends that cesarean delivery be limitedto estimated fetal weights of at least5000 g in womenwithout diabetes and atleast 4500 g in women with diabetes(Table 3).99 This recommendation isbased on estimations of the numberneeded to treat from a study that mod-eled the potential risks and benefits froma scheduled, nonmedically indicated ce-sarean delivery for suspected fetal mac-rosomia, including shoulder dystociasand permanent brachial plexus in-juries.100 The prevalence of birth weightof �5000 g is rare, and patients shouldbe counseled that estimates of fetalweight, particularly late in gestation, areimprecise (Table 3). Even when thesethresholds are not reached, screeningultrasonography performed late inpregnancy has been associated with theunintended consequence of increasedcesarean delivery with no evidence ofneonatal benefit.101 Thus, ultrasonogra-phy for estimated fetal weight in thethird trimester should be used sparinglyand with clear indications.

Excessive maternal weight gainA large proportion of women in theUnited States gain more weight duringpregnancy than is recommended by theInstitute of Medicine (IOM). Observa-tional evidence suggests that womenwhogain more weight than recommended bythe IOMguidelines have an increased riskof cesarean delivery and other adverseoutcomes.15,102,103 In a recent Commit-tee Opinion, ACOG recommends that itis “important to discuss appropriateweight gain, diet, and exercise at the ini-tial visit and periodically throughoutthe pregnancy.”104 Although pregnancy

weight-management interventions con-tinue to be developed and have yet totranslate into reduced rates of cesareandelivery or morbidity, the availableobservational data support that womenshould be counseled about the IOMmaternal weight guidelines in an attemptto avoid excessive weight gain (Table 3).

Twin gestationThe rate of cesarean deliveries amongwomen with twin gestations increasedfrom 53% in 1995 to 75% in 2008.105

Even among vertex-presenting twins,there was an increase from 45-68%.105

Perinatal outcomes for twin gestations inwhich the first twin is in cephalic pre-sentation are not improved by cesareandelivery. Thus, women with eithercephalic/cephalic-presenting twins orcephalic/noncephalic-presenting twinsshould be counseled to attempt vaginaldelivery (Table 3).106 To ensure safevaginal delivery of twins, it is importantto train residents to perform twin de-liveries and to maintain experience withtwin vaginal deliveries among practicingobstetric care providers.

Herpes simplex virusIn women with a history of herpes sim-plex virus, the administration of acyclo-vir for viral suppression is an importantstrategy to prevent genital herpetic out-breaks requiring cesarean deliveryand asymptomatic viral shedding.107,108

Given the favorable benefit-risk profilefor the administration of maternal acy-clovir, efforts should be made to ensurethat women with a history of genitalherpes, even in the absence of an out-break in the current pregnancy, areoffered oral suppressive therapy within3-4 weeks of anticipated delivery109 andat the latest, �36 weeks of gestation.110

Cesarean delivery is not recommendedfor women with a history of herpessimplex virus infection but no activegenital disease during labor.110

Continuous labor and delivery supportPublished data indicate that one ofthe most effective tools to improvelabor and delivery outcomes is the con-tinuous presence of support personnel,such as a doula. A Cochrane meta-analysis of 12 trials and>15,000 women

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demonstrated that the presence of con-tinuous one-on-one support duringlabor and delivery was associated withimproved patient satisfaction and a sta-tistically significant reduction in the rateof cesarean delivery.111 Given that thereare no associated measurable harms, thisresource is probably underutilized.

What organizational actions arenecessary for the primary cesareandelivery rate to safely decline?

A number of approaches are needed toreduce the primary cesarean deliveryrate, which in turn would lower therepeat cesarean delivery rate. Althoughnational and regional organizations cantake the lead in setting the agendaregarding the safe prevention of primarycesarean delivery, such an agenda willneed to be prioritized at the level ofpractices, hospitals, health care systems,and, of course, patients.

Changing the local culture and atti-tudes of obstetric care providers regardingthe issues involved in cesarean deliveryreduction also will be challenging. Severalstudies have demonstrated the feasibilityof using systemic interventions to reducethe rate of cesarean delivery across in-dications and across community and ac-ademic settings. A 2007 review found thatthe cesarean delivery rate was reduced by13% when audit and feedback were usedexclusively but decreased by 27% whenaudit and feedback were used as part of amultifaceted intervention, which involvedsecond opinions and culture change.112

Systemic interventions, therefore, providean important strategic opportunity forreducing cesarean delivery rates. How-ever, the specific interventional ap-proaches have not been studied in large,prospective trials, thus specific recom-mendations cannot be made.

A necessary component of culturechange will be tort reform becausethe practice environment is extremelyvulnerable to external medicolegalpressures. Studies have demonstratedassociations between cesarean deliveryrates and malpractice premiums andstate-level tort regulations, such ascaps on damages.113,114 A broad rangeof evidence-based approaches will be



necessaryeincluding changes in indi-vidual clinician practice patterns, devel-opment of clinical managementguidelines from a broad range of orga-nizations, implementation of systemicapproaches at the organizational leveland regional level, and tort reformetoensure that unnecessary cesarean de-liveries are reduced. In addition, in-dividuals, organizations, and governingbodies should work to ensure thatresearch is conducted to provide a betterknowledge base to guide decisionsregarding cesarean delivery and toencourage policy changes that safelylower the rate of primary cesarean de-livery (Table 3). -

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http://www.uptodate.com/home/grading-guide

http://www.uptodate.com/home/grading-guide


Appendix

Society for MaternaleFetal Medicine grading system: grading of recommendationsassessment, development, and evaluation (GRADE) recommendations

Obstetric Care Consensus documents will use Society for MaternaleFetal Medicine grading approach: http://www.ajog.org/article/S0002-9378%2813%2900744-8/fulltext.

Recommendations are classified as either strong (Grade 1) or weak (Grade 2), and quality of evidence is classified as high (Grade A), moderate(Grade B), and low (Grade C).118 Thus, recommendations can be 1 of following 6 possibilities: 1A, 1B, 1C, 2A, 2B, 2C

Grade ofrecommendation Clarity of risk and benefit Quality of supporting evidence Implications

1A. Strongrecommendation,high-quality evidence

Benefits clearly outweigh risk andburdens, or vice versa.

Consistent evidence from well-performedrandomized controlled trials or overwhelmingevidence of some other form. Further researchis unlikely to change confidence in estimate ofbenefit and risk.

Strong recommendations,can apply to most patients inmost circumstances withoutreservation. Cliniciansshould follow strongrecommendation unlessclear and compellingrationale for alternativeapproach is present.

1B. Strongrecommendation,moderate-qualityevidence

Benefits clearly outweigh risk andburdens, or vice versa.

Evidence from randomized controlled trials withimportant limitations (inconsistent results,methodological flaws, indirect or imprecise), orvery strong evidence of some other researchdesign. Further research (if performed) is likelyto have impact on confidence in estimate ofbenefit and risk and may change estimate.

Strong recommendation, andapplies to most patients.Clinicians should followstrong recommendationunless clear and compellingrationale for alternativeapproach is present.

1C. Strongrecommendation,low-quality evidence

Benefits appear to outweigh riskand burdens, or vice versa.

Evidence from observational studies,unsystematic clinical experience, or fromrandomized controlled trials with serious flaws.Any estimate of effect is uncertain.

Strong recommendation, andapplies to most patients.Some of evidence basesupporting recommendationis, however, of low quality.

2A. Weakrecommendation,high-quality evidence

Benefits closely balanced withrisks and burdens.

Consistent evidence from well-performedrandomized controlled trials or overwhelmingevidence of some other form. Further researchis unlikely to change confidence in estimate ofbenefit and risk.

Weak recommendation, bestaction may differ dependingon circumstances or patientsor societal values.

2B. Weakrecommendation,moderate-qualityevidence

Benefits closely balanced withrisks and burdens; someuncertainty in estimates ofbenefits, risks, and burdens.

Evidence from randomized controlled trials withimportant limitations (inconsistent results,methodological flaws, indirect or imprecise), orvery strong evidence of some other researchdesign. Further research (if performed) is likelyto have effect on confidence in estimate ofbenefit and risk and may change estimate.

Weak recommendation,alternative approaches likelyto be better for some patientsunder some circumstances.

2C. Weakrecommendation,low-quality evidence

Uncertainty in estimates ofbenefits, risks, and burdens;benefits may be closely balancedwith risks and burdens.

Evidence from observational studies,unsystematic clinical experience, or fromrandomized controlled trials with serious flaws.Any estimate of effect is uncertain.

Very weak recommendation,other alternatives may beequally reasonable.

Best practice Recommendation in which either: (i) there is enormous amount of indirect evidence that clearly justifies strongrecommendation (direct evidence would be challenging, and inefficient use of time and resources, to bring together andcarefully summarize), or (ii) recommendation to contrary would be unethical.

Modified from grading guide.119



http://www.ajog.org/article/S0002-9378%252813%252900744-8/fulltext

http://www.ajog.org/article/S0002-9378%252813%252900744-8/fulltext

ACOG/SMFM Consensus Advance... · 2014. 4. 9. · ACOG/SMFM OBSTETRIC CARE CONSENSUS Safe...

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