Lowering the Cesarean Delivery Rate: Is the horse out of the barn? Bob Silver University of Utah Salt Lake City, Utah

Transcription

1 Lowering the Cesarean Delivery Rate: Is the horse out of the barn? Bob Silver University of Utah Salt Lake City, Utah

2 Trends Dramatic and steady increase One third of US deliveries!!!! % of deliveries 1.4 million women Most common major surgery Increased by > 50% since1996 Accelerated since 2000 All ages, races, states, gestational ages Hamilton et al. NVS reports 2012

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4 Menacker et al. NCHS Data Brief 2010; # 35

5 Menacker et al. NCHS Data Brief 2010; # 35

6 Menacker et al. NCHS Data Brief 2010; # 35

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8 US States Best: Alaska 22.6% New Mexico, Utah (23.1%), Idaho (24.8%), Colorado Worst: Louisiana 39.7% New Jersey, Florida, Mississippi Hamilton et al. NVS reports 2012

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10 US data Data from birth certificates All states since 1991 Revised birth certificate Some states (2003) Comparable data on total CS Data differ regarding prior CS, VBAC, 1 0 CS 2007: 22 states used revised certificates»53% of all US births» Mexican women are over-represented MacDorman et al. Clin Perinatol 2011; 38:179

11 Since 1996, both primary and repeat CS have increased Primary CS: 1996: 14.6% of births 2004: 20.6% of births 2007: 23.4% (22 states) VBAC: Why the increase? 1996: 28.3% 2004: 9.2% 2007: 8.3% (22 states) MacDorman et al. Clin Perinatol 2011; 38:179

12 MacDorman et al. Clin Perinatol 2011; 38:179

13 MacDorman et al. Clin Perinatol 2011; 38:179

14 Why the increase? Latin America 120 Randomly selected hospitals 8 countries 97,095 pregnancies CS rate: 35% (range: 0 85%) Risk adjusted CS rate: 11% - 85%! Institutional characteristics: 48% variability! practice patterns! Taljaard et al. Paediatric and Perinatal Epidem 2009; 23:574

15 Why the increase? British Columbia Excluded women with prior CS 116,839 deliveries (16 areas) Primary CS range: 16.1 to 27.5% Adjusted primary CS range: 14.7 to 27.6% - practice patterns! Dystocia: 30% of primary CS Variability in forceps / vacuum also Hanley et al. Obstet Gynecol 2010; 115:1201

16 Classification 10 group classification 4 characteristics Single / multiple Multiparity / CS scar Spontaneous / induced labor Term (> 37 weeks) E.g. group 1 nullipara, single, cephalic, > 37 weeks, spontaneous labor Allows comparison of different populations Brennan et al, Am J Obstet Gynecol 2009;201:e1-8

17 Classification Nulliparous, term, singleton, vertex NTSV Cesarean birth versus vaginal birth Simple comparative measure of CS rates Strongly influenced by OB practices Considerable variation Main et al, Am J Obstet Gynecol 2006;194:1644

18 Why the increase? Consortium on Safe Labor 19 hospitals: ,668 patients (EMRs) CS rate: 30.5% (31.5% Nullips) 1/3 CS prior CS 47% intrapartum CS - dystocia 27.3% intrapartum CS fetal distress 47% TOL Inductions! Inductions 2X CS rate (vs spontaneous labor) Zhang et al. Am J Obstet Gynecol 2010; 203:326

19 Why the increase? Yale-New Haven hospital ,443 live births CS rate increased: 26% % 50% of the increase primary CS Non-reassuring fetal status: 32% Labor arrest disorders: 18% Multiple gestation: 18% Suspected macrosomia : 10% Maternal request: 8% Barber et al. Obstet Gynecol 2011; 118:29

20 Why the increase? National Maternity Hospital CS rates group classification system Overall CS rate: 5% % Nulliparous, term, singleton, cephalic CS rate: 4.4% % Inductions: 19.7% % CS Inductions: 4.1% % 69% of increase in CS rate attributed to induction! Brennan et al. Obstet Gynecol 2011; 117:273

21 Brennan et al. Obstet Gynecol 2011; 117:273

22 Why the increase? Christiana Hospital Nulliparous, term, singleton, vertex ; 7,804 women Labor induction: 43.6% Elective induction: 39.9% inductions OR for CS: 2.67 ( ) Adjusted OR for CS: 1.93 ( ) Responsible for 20% of CS Ehrenthal et al. Obstet Gynecol 2010; 116:35

23 Why the increase? Multiple gestation Singleton births: 30.8% CS Twins 75.4% CS Triplets or higher order births 94.6% CS MacDorman et al. Clin Perinatol 2011; 38:179

24 Why the increase? Obesity Maternal age No vaginal breech deliveries Fewer operative deliveries Cesarean on maternal request MacDorman et al. Clin Perinatol 2011; 38:179

25 Why the increase? Abnormal labor Inductions Abnormal fetal heart rate tracings Fewer TOLACs / VBACs Everything else is chump change Breech Multiple gestation Decreased operative vaginal delivery

26 Do we care? Cesareans are safe Major complications are rare Some women choose cesarean delivery Potential benefits: pelvic floor Potential benefits: stillbirth / asphyxia Convenient Families Doctors

27 Maternal Mortality & Morbidity Canada: Planned CS (Breech) (N = 46,766) Planned TOL (N = 2,292,420) Planned CS: Cardiac arrest: OR 5.1 ( ) Wound hematoma: OR 5.1 ( ) Hysterectomy: OR 3.2 ( ) Major infection: OR 3.0 ( ) Liu et al CMAJ 2007;176:455

28 Maternal Mortality & Morbidity Canada: Planned CS: Anesthetic comps: OR 2.3 ( ) VTE: OR 2.2 ( ) Hemorrhage / Hyst: OR 2.1 ( ) Hemorrhage / TX: OR 0.4 ( ) Longer hospital stay: 1.47 days ( ) Low absolute risks Liu et al CMAJ 2007;176:455

29 Maternal Death Observational cohort Netherlands 1,872,586 births (5.8% Cesarean) 154 maternal deaths 0.04 (per 1,000) NSVD 0.53 (per 1,000) Cesarean 17% of deaths directly due to cesarean Direct risk: 0.13/1,000 cesareans Schuitemaker et al, Acta Obstet Gynecol Scand 1996;75:332

30 Maternal Death Observational cohort Canada 308,755 women with prior cesarean Trial of labor versus repeat cesarean Wen et al., Am J Obstet Gynecol 2004;191:1263

31 Maternal Death Deaths per 100,000 Vaginal birth: 1.9 CS: 17.3 Trial of labor: 2.1 Elective CS: 11.0 Wen et al., Am J Obstet Gynecol 2004;191:1263

32 Maternal Death Risk ratio (relative to trial of labor) Elective CS: 5.25 (1.58, 17.49) All CS: 9.11 (6.62, 12.53) Wen et al., Am J Obstet Gynecol 2004;191:1263

33 Maternal Mortality Vaginal delivery: 0.2 deaths per 100,000 Cesarean delivery: 2.2 deaths per 100, deaths due to CS / year (thrombosis) Clark et al; AJOG 2008;199:36e5

34 Maternal Deaths in the US

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36 Severe Obstetric Morbidity USA: : 0.64% : 0.81% Renal failure: 21% increase Pulmonary embolus: 52% increase ARDS: 26% increase Shock: 24% increase Blood transfusion: 92% increase Ventilation: 21% increase Kuklina et al Obstet Gynecol 2009;113:293-9

37 Severe Obstetric Morbidity USA: Regression models: Age, payer, multiple births, comorbidities no effect Mode of delivery increased risks were no longer significant (except PE and blood TX) Many complications were associated with cesarean delivery! Kuklina et al Obstet Gynecol 2009;113:293-9

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39 Placenta Accreta Incidence 1960s: 1 in 30,000 deliveries : 1 in 2,510 deliveries : 1 in 533 deliveries : 1 in 333 deliveries! Miller et al., AJOG 1997;177:210 Wu et al., AJOG 2005;192:1458 Pub Committee SFMFM; Belfort, Am J Obstet Gynecol 2010;430-8

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41 Cost 18 year population based study Nova Scotia Database Cumulative costs in pregnancy hospitalization Nulliparas, cephalic, singleton, planned TOL 27, 613 pregnancies cumulative costs 1 st pregnancy: Induction: $ 7,220 1 st pregnancy: Spontaneous labor: $ 6,919 Allen et al., Obstet Gynecol 2006;108:549

42 Cost Cumulative costs (deliveries 1, 2 & 3) Spontaneous vaginal delivery: $ 6,425 Assisted vaginal delivery: $ 7,288 Cesarean delivery: $ 9,524 Allen et al., Obstet Gynecol 2006;108:549

43 Other stuff Long term maternal / reproductive issues Breast feeding Bonding Flow / space in hospitals Larger Obstetric wards More ORs More CS slots Obstetric training

44 Do we care? We Should!

45 Reduction Strategies Clinical interventions Active management of labor Policies regarding indications for CS Non-clinical interventions Targeting patients education / psychology Targeting physicians Peer review Second opinion Education Reimbursement

46 Reduction Strategies RCT of Collaboration in maternity care Midwives and obstetricians Community model: N = 550 Standard care: N = 539 Teaching hospital: Sydney, Australia Primary outcome CS rate: Community model: 13.3% Standard care: 17.8% OR 0.6 (95% CI ; p = 0.02) Homer et al., Br J Obstet Gynecol 2001;108:16

47 Reduction Strategies RCT of Active Management of Labor Spontaneous labor, term, early amniotomy, aggressive oxytocin Northwestern (Private University Hospital) ; intrapartum randomization Controls (N = 351): CS 14.1% Active management (N = 354): CS 10.5% (22% ) OR for CS: 0.57 (95% CI ) Decreased CS for dystocia Lopez-Zeno et al., N Engl J Med 1992;326:450

48 Reduction Strategies RCT of Active Management of Labor Spontaneous labor, term, early amniotomy, aggressive oxytocin, classes, true labor Brigham and Women s (Private University Hospital) ; randomizaton: 30 wks Active management (N = 1017): CS 19.5% Controls (N = 917): CS 19.4% Low risk subgroup: CNMs Still no difference in CS: 10.9% vs 11.5% Frigoletto et al., N Engl J Med 1995;333:745

49 Reduction Strategies Natural history: normal first stage of labor National Collaborative Perinatal Project 26,838 deliveries Singleton, term, spont labor, normal outcome 12 hospitals; Observational study Active phase may not start until 5 cm! Two hour threshold for dystocia: Too short prior to 6 cm? No CS for 1 st stage arrest until 6 cm Zhang et al., Obstet Gynecol 2010;115:705

50 Reduction Strategies Natural history: normal second stage of labor Safe labor Consortium 62,415 deliveries; observational study Singleton, term, normal outcome Second stage: median / 95% Nullipara / epidural: 1.1 / 3.6 hours Nullipara / no epidural: 0.6 / 2.8 hours Multipara / epidural: 0.3 / 1.6 hours Multipara / no epidural: 0.1 / 1.1 hours Redefine criteria for second stage arrest Zhang et al., Obstet Gynecol 2010;116:1281-7

51 Reduction Strategies RCT of Mandatory second opinion for CS 34 hospitals in Latin America Mandatory second opinion in intervention hospitals (non-blinded) 149, 276 deliveries CS Rate reduction with intervention: 7.3% (95% CI % Mostly intrapartum CS 22 CS prevented per 1,000 deliveries Althabe et al., Lancet 2004;363:1934

52 Mandated policy for labor management intended to reduce CS for dystocia Medical audit pre and post Penbury, UK 21, 125 deliveries Overall CS rate: 12% to 9.5% CS rate nulliparas, labor, term, cephalic 7.5% to 2.4% Reduction Strategies Robson et al., Am J Obstet Gynecol 1996;174:199

53 Reduction Strategies Multifaceted approach Encouragement of TOLAC Feedback on individual CS rates Active management of labor encouraged Private University hospital (Northwestern) 1986 pre; 1991 post Total CS: 27.3% to 16.9% Primary CS: 18.2% to 10.6% Repeat CS: 9.1% to 6.4% Increased TOL, decreased CS for dystocia Socol et al., Am J Obstet Gynecol 1993;168:1748

54 Reduction Strategies Financial incentives Taiwan 2005: National health insurance equalized fee for CS and vaginal delivery Fee equivalence policy No effect on CS rate! Lo, Health Policy 2008;88:121

55 Reduction Strategies Financial incentives California Blue Cross Equalized fee for CS and vaginal delivery No meaningful effect on CS rates! Keeler, Med Care Research Rev 1996;53:465

56 Leisure incentives Fatigue, workload, anticipated lost sleep Physician motivated to sleep or go home Increased CS rate Financial incentives may play a role Salaried docs / profit sharing Lower CS rate Reduction Strategies Spetz et al, Med Care 2001;118:29-38 Klasko et al, Am J Obstet Gynecol 1995;172: Macones et al, Obstet Gynecol 2008;112:661-6

57 Reduction Strategies Departmental policies 1994 Labor management and CS guidelines Peer review of all CS outside of guidelines 24 hour in house coverage Community hospital Pre-intervention: CS rate 22.5% (1 0 : 13.5%) Post-intervention: CS rate 18.6% (1 0 : 10.6%) Increased oxytocin and vacuum No change in morbidity and mortality Poma, Am J Obstet Gynecol 1998;91:1013

58 External peer review Joint Specialty Society and Health Department New York State Reduction Strategies 45/165 hospitals; CS rates pre and post intervention Reviewed hospitals: CS decreased 3% and RCS decreased 0.7% Non-reviewed hospitals: CS decreased 1% and RCS decreased 0.6% No Statistical difference Bickell et al, Obstet Gynecol 1996;87:664

59 Reduction Strategies Obstetric peer review interventions Netherlands 1994 Annual comparison data (adjusted) for obstetric interventions Departments randomized to be informed about results No difference in CS rates (or other obstetric interventions) in group exposed to data Elferink-Stinkens et al, Eur J Obstet Gynecol 2001;102:21

60 Reduction Strategies Cesarean surveillance system Pre-cesarean surveillance Weekly conference review of all CS Taiwan 1997 Rates pre and post intervention Pre: CS rate 37.0%; 1 0 CS: 21.3% Post: CS rate 30.0%; 1 0 CS: 17.8% Liang et al, J Chin Med Assoc 2004;67:281

61 Reduction Strategies Multifaceted action plan Learning sessions directed by experts Three 2 day sessions / year Weekly conference calls internet 28 organizations CS reduced by 30% or more: 15% CS reduced by 10 30%: 50% Flamm et al, Birth 1998;25:117

62 STAN: 3 RCTs in Cochrane Database Operative Delivery for Fetal Distress Metaboli c Acidosis Plymouth RCT N = 2434 Swedish RCT N = 4966 Finnish RCT N = 1483 Control 9.1% 9.3% 6.4% (CS) 9.5% (OVD) STAN 5.0%* 7.7%* 4.7% (CS) 10.7% (OVD) Control 1.40% 1.44% 0.7% STAN 0.55%* 0.57%* 1.7% * = p < 0.05

63 STAN MFMU: RCT > 36 weeks, attempting vaginal delivery, 2-7 cm Randomized: Open or masked STAN All providers STAN certified 11,108 pregnancies (5,532 open / 5,576 masked) Cord ph available for 96.5% No difference in groups: Fetal / neonatal death / low Apgar, ph < 7.05, base deficit > 12 CS / operative vaginal delivery NICU admit / meconium aspiration / shoulder dystocia Saade et al.; SMFM 2015

64 Reduction Strategies Meta-analysis Evidence based strategies Medline 10 studies included 2 cluster RCTs 3 RCTs 5 interrupted time series 4 audit and feedback 4 quality improvement 2 multifaceted Chaillet and Dumont, Birth 2007;1

65 Reduction Strategies Overall intervention RR: 0.81 ( ) Audit / Feedback RR: 0.87 ( ) Quality improvement RR: 0.74 ( ) Mixed results for active management of labor Higher effect in non-rcts Higher effect if studies ID barriers to change No increase in morbidity / mortality Conclude that multifaceted strategies are effective and should be adopted Chaillet and Dumont, Birth 2007;1

66 Non-clinical interventions Review 16 studies included 6 studies targeted pregnant women Two were effective RCT nurse led relaxation program RCT birth preparation sessions Small studies Reduction Strategies Insufficient evidence to recommend perinatal education, support, computer decision aids, decision aid booklets and group therapy Tavender et al, Cohchrane review 2011;6

67 Reduction Strategies 10 studies targeted health professionals Three were effective Cluster RCT guidelines / second opinion RD -1.9 ( ) ITS study second opinion / feedback RD -6.4% (-9.7% %) Cluster RCT Guidelines / opinion leaders Increased TOLAC 16.% / VBAC 13.5% Tavender et al, Cohchrane review 2011;6

68 Multifaceted Intervention Cluster-RCT 32 hospitals in Quebec Multifaceted intervention: Audits of CS indications Feedback to providers Implementation of best practices 184, 952 participants 53,086 year prior to intervention 52,265 year after intervention Chaillet et al, N Engl J Med 2015;372:

69 Multifaceted Intervention Cesarean delivery: Intervention: 22.5% to 21.8% Control: 23.2% to 23.5% aor 0.9 (95% CI, ) arisk Difference 1.8% (95% CI, -3.8 to 0.2) Cesarean rate was significantly lower in lowrisk but not high-risk pregnancies Neonatal morbidity: Slight decrease in major and increase in minor for intervention group Chaillet et al, N Engl J Med 2015;372:

70 Reduction Strategies NICHD / SMFM Workshop 2012 Preventing the first cesarean Expert talks Medical / Non-medical / long term issues Discussion Recommendations Spong et al, Obstet Gynecol 2012;120:

71 Reduction Strategies Labor induction Primarily for medical indications If non-medical: Must be 39 weeks gestation If non-medical: Must have a favorable cervix Especially nulliparous women Spong et al, Obstet Gynecol 2012;120:

72 Labor induction Cesarean Delivery Reduction Strategies > 50% remain in latent phase for 6 hours > 20% remain in latent phase for 12 hours 40% of women in latent phase after 12 hours deliver vaginally Simon and Grobman, Obstet Gynecol 2005;105:705-9 Harper et al, Obstet Gynecol 2012;119: Rouse et al, Obstet Gynecol 2011;117:267-72

73 Failed induction Cesarean Delivery Reduction Strategies Allow adequate time for vaginal delivery Distinguish between failed induction and first stage arrest No regular contractions and cervical change after at least 24 hours oxytocin and AROM if possible Can go longer if non-urgent induction Spong et al, Obstet Gynecol 2012;120:

74 Reduction Strategies First stage arrest 6 cm dilation AROM NO cervical change 4 hours with adequate contractions 6 hours if inadequate contractions Spong et al, Obstet Gynecol 2012;120:

75 Reduction Strategies Second stage arrest NO progress (descent or rotation) 4 hours nulliparas / epidural 3 hours nulliparas / no epidural 3 hours multiparas / epidural 2 hours multiparas / no epidural Spong et al, Obstet Gynecol 2012;120:

76 Reduction Strategies Second stage arrest NO progress (descent or rotation) 4 hours nulliparas / epidural 3 hours nulliparas / no epidural 3 hours multiparas / epidural 2 hours multiparas / no epidural Spong et al, Obstet Gynecol 2012;120:

77 Reduction Strategies Operative vaginal delivery Acceptable and safe option Should encourage use Should encourage education, training and experience Spong et al, Obstet Gynecol 2012;120:

78 Reduction Strategies Discussing first cesarean Include short term risks Include long-term risks Future reproductive issues Spong et al, Obstet Gynecol 2012;120:

79 Reduction Strategies Non-medical factors Consider salaried physicians and profit sharing models Hospitalist model Reduce non-medical incentives to perform cesareans? Medicolegal strategies Spong et al, Obstet Gynecol 2012;120:

80 Reduction Strategies Quality Measures each Obstetrician Singleton, term, vertex Rate of non-medically indicated CS Rate of non-medically indicated induction Rate of labor arrest or failed induction without meeting accepted criteria Rate of CS for abnormal fetal heart rate tracing by category of tracing Spong et al, Obstet Gynecol 2012;120:

81 What might really help? Reduce unnecessary inductions! Nulliparas wait until 41 weeks gestation Multiparas 39 weeks favorable cervix Revise criteria for labor arrest 6 cm or more 1 st stage? 4 hours with no change on oxytocin Allow longer second stage Peer review of CS for dystocia Active management of labor? STAN???? Nope!!!!!!

82 What might really help? Better strategies to assess fetal status Scalp ph New technology Peer review Engage hospital administration QA Cost efficiency IT Engage / educate patients

83 Induction and cesarean delivery: Common wisdom Retrospective cohort studies Induction of labor prior to 41 weeks of gestation is associated with an approximately 2-fold higher risk of cesarean delivery in nulliparous women

84 Elective inductions only

85 Standard of Care Patients undergoing induction of labor should be counseled about a 2 fold increased risk of cesarean ACOG #107 Obstet Gynecol 2009; 114:386-97

86 The problem Spontaneously laboring women are not the right comparison group Cannot choose between EIOL (strategy) and spontaneous labor (event) Choice is between EIOL and expectant management The latter may lead to spontaneous labor Also conveys downstream possibilities that may increase the CS rate

87 Induction vs. Expectant Management RCT of women at 41 weeks of gestation (N = 3407) CS % Hannah et al, NEJM, 1992

88 IOL prior to 41 weeks: HYPITAT IOL vs. expectant management for mild hypertensive disease after 36 weeks (N = 756) IOL Adverse maternal composite: RR 0.71 ( ) Cesarean Delivery P =.09 % Koopmans et al. Lancet 2009; 374:979-88

89 Induction vs. Expectant Management (CS%) Week of Induction IOL Spontaneous 38 weeks 11.9% 7.0% 39 weeks 14.3% 9.1% 40 weeks 20.4% 10.9% 41 weeks 24.3% 14.9% Caughey et al, AJOG 2006;195:700-5

90 Induction vs. Expectant Management (CS%) Week of Induction IOL Spontaneous Expectant aor (95% CI) 38 weeks 11.9% 7.0% 13.3% 1.80 ( ) 39 weeks 14.3% 9.1% 15.0% 1.39 ( ) 40 weeks 20.4% 10.9% 19.0% 1.24 ( ) 41 weeks 24.3% 14.9% 26.0% 1.26 ( ) Caughey et al, AJOG 2006;195:700-5

91 EIOL vs. expectant management Retrospective Cohorts: Northwestern 588 women at 39 weeks with favorable cervix Power: 1/3 reduction in CS from 30% at EIOL 204 women at 39 weeks with unfavorable cervix Power: 1/2 reduction in CS from 40% at EIOL Osmundson et al. Obstet Gynecol 2010; 116:601-5 Osmundson et al. Obstet Gynecol 2011; 117:583-7

92 % Osmundson et al. Obstet Gynecol 2010; 116:601-5 Osmundson et al. Obstet Gynecol 2011; 117:583-7

93 EIOL vs. expectant management at 39 weeks Cesarean delivery % Expectant IOL 0 Cheng et al Stock et al 10% decreased odds of cesarean in EIOL group Cheng et al AJOG 2012; Stock et al BMJ 2012

94 RCT of EIOL prior to 41 weeks Six small RCT s None have found an increase in cesarean delivery Poor quality Underpowered

95 EIOL vs. expectant management at 39 weeks 0.35 Perinatal mortality and morbidity % Expectant IOL 0 Cheng et al Stock et al 70% decreased odds of mec aspiration and mortality, respectively, in EIOL group Cheng et al AJOG 2012; Stock et al BMJ 2012

96 Elective Induction vs Expectant Management Retrospective cohort study California deliveries in 2006 No prior cesareans weeks gestation Elective induction compared to expectant management at each gestational age Vertex, non-anomalous, singleton deliveries (N = 362, 154) Darney et al. Obstet Gynecol 2013; 122:761-9

97 Elective Induction vs Expectant Management Overall CS rate: 16% Perinatal mortality: 0.2% NICU admission: 6.2% OR for CS was LOWER at all gestational ages and parity for EIOL!! EIOL NOT associated with severe lacerations, operative vaginal delivery, shoulder dystocia, etc. Darney et al. Obstet Gynecol 2013; 122:761-9

98 Elective Induction vs Expectant Management OR for CS with EIOL 37 weeks: 0.44 ( ) 38 weeks: 0.43 ( ) 39 weeks: 0.46 ( ) 40 weeks: 0.57 ( ) EIOL increased hyperbilirubinemia at 37 and 38 weeks gestation Darney et al. Obstet Gynecol 2013; 122:761-9

99 Conclusions We know that at weeks, IOL better than EM We know that before 39 weeks, EM better than IOL Between 39 and 41 weeks: Common wisdom that EM is better than IOL Maternal and neonatal outcomes worsen with delivery after 39 weeks The concern that IOL increases CD is founded on methodologically flawed study design Common practice is moving away from EM We actually don t know whether EM or IOL is better

100 Induction in Nulliparous Women at 39 Weeks to Prevent Adverse Outcomes: A Randomized Controlled Trial A Randomized Trial of Induction Versus Expectant Management (ARRIVE)