The evidence-based case to induce all normal pregnancies ... · 70 CS rate= 31%. Induction vs. Expectant Management Week of Induction IOL Spontaneous 38 weeks 11.9% 7.0% 39 weeks

WILLIAM GROBMAN, MD,MBAARTHUR HALE CURTIS PROFESSORDEPARTMENT OF OBSTETRICS AND

GYNECOLOGYFEINBERG SCHOOL OF MEDICINE

NORTHWESTERN UNIVERSITY

The evidence-based case to induce all normal pregnancies at 39 weeks

GOU, 2017

When is the best time for delivery?

Delivery Expectant management

≥ 42 weeks < 39 weeks

39 - 41 weeks41 weeks

Increasing maternal and perinatal risks after 39 weeks

Maternal Complications

● Pregnancies that continue beyond 39 weeks are associated with increased risks of: ○ Cesarean delivery○ Operative vaginal delivery○ 3rd and 4th degree lacerations○ Febrile morbidity○ Hemorrhage

Statistical significance as compared to rate of cesarean delivery in the previous week gestation*p<.05

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Statistical significance as compared to rate of outcome in the previous week gestation: *p<.05

Perinatal Complications

● Pregnancies that continue beyond 39 weeks are associated with increased risks of:○ Stillbirth○ Meconium aspiration syndrome○ Mechanical ventilation○ Birth trauma○ Neonatal seizures/ICH/ encephalopathy○ Neonatal sepsis○ UA pH ≤7/BE < -12

Severe Neonatal Complications

40 vs. 39 weeks: adjusted OR 1.47 (1.1, 2.0)41 vs. 39 weeks : adjusted OR 2.04 (1.5, 2.78)

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

39 weeksN= 100

CS rate=20%N=6

IOL

CS rate=30%N=35

30% Spontaneous laborat 39 weeks

CS rate=30%N=11

50% labor at 40 weeks

CS rate=40%N=14

35

N=100

Medical or Post dates IOL

70

CS rate=31%

Induction vs. Expectant Management

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

Induction vs. Expectant Management

Week of Induction

IOL Spontaneous Expectant aOR (95% CI)

38 weeks 11.9% 7.0% 13.3% 1.80 (1.29-2.53)

39 weeks 14.3% 9.1% 15.0% 1.39 (1.08-1.80)

40 weeks 20.4% 10.9% 19.0% 1.24 (1.27-1.62)

41 weeks 24.3% 14.9% 26.0% 1.26 (0.99-1.61)

Caughey et al, AJOG 2006;195:700-5

EIOL vs. expectant management at 39 weeks

%

Cheng et al AJOG 2012; Stock et al BMJ 2012

Cesarean delivery

10% decreased odds of cesarean in EIOL group

Cesarean delivery with EIOL

%

Osmundson et al, Obstet Gynecol 2010 & 2011

RCTs?

Induction vs. Expectant Management

○ RCT of women at 41 weeks of gestation (N = 3407)

Hannah et al, NEJM, 1992

%

RCT of EIOL prior to 41 weeks –Until 2016….

●Only small RCT’s●None have found an increased in cesarean

delivery○ Poor quality○ Underpowered

Walker et al, NEJM 2016

● 619 nulliparous women ● Age 35 years or older● Randomized between 36 weeks and 39 6/7 weeks

%

Cesarean Delivery

Walker et al, NEJM 2016

●Only women aged 35 or older●No idea about cervical status●UK system very different (e.g., OVD)●Underpowered for perinatal outcomes

Perinatal outcomes with EIOL?

EIOL vs. expectant management at 39 weeks

%

Cheng et al AJOG 2012; Stock et al BMJ 2012

Perinatal mortality and morbidity

70% decreased odds of mec aspiration and mortality, respectively, in EIOL group

IOL vs. expectant management

CMAJ2014

NICU admission: RR 0.86, 95% CI 0.79 – 0.94

Fetal death: RR 0.50, 95% CI 0.25 – 0.99

Maternal death: RR 1.00, 95% CI 0.1 – 9.57

Resource utilization

●Osmundson et al, 2010/2011○ Labor induction

• Favorable cervix: 3.7 additional L&D hours• Unfavorable cervix: 3.8 additional L&D hours

●Vijgen, BJOG 2010 (Hypitat)○ Total costs 11% less for IOL (€831)

DOES NOT ACCOUNT FOR ANTEPARTUM COSTS

Resource utilization

● Walker et al, BJOG 2017○ Induction cheaper by £236 and increases QALY by .002

A RANDOMIZED TRIAL OF INDUCTION VERSUS

EXPECTANT MANAGEMENT

A RANDOMIZED TRIAL OF INDUCTION VERSUS

EXPECTANT MANAGEMENT

(ARRIVE)

Inclusion criteria

● Nulliparous● Singleton gestation● Adequate dating

Protocol

● Randomization between 38-38 6/7 to:○ Elective induction of labor between 39 and 39 4/7 weeks○ Expectant management

● Cervical exam at randomization

IOL Group

● Favorable: oxytocin ● Unfavorable: cervical ripening followed by oxytocin

Expectant Management

● Unless a medical indication is present, will continue pregnancy until at least 40 5/7 weeks of gestation

● Antepartum fetal testing (per institutional protocol) always will be initiated no later than 41 weeks for all ongoing pregnancies

● All patients delivered no later than 42 2/7 weeks

Primary Perinatal Outcome

Composite of neonatal morbidity and perinatal mortality● Antepartum, intrapartum, or neonatal death● Intubation, continuous positive airway pressure (CPAP) or high-flow nasal cannula (HFNC) for ventilation or cardiorespiratory support within first 72 hours ● Apgar ≤ 3 at 5 minutes ● Neonatal encephalopathy ● Seizures ● Sepsis● Meconium aspiration syndrome● Birth trauma (bone fractures, brachial plexus palsy, other neurologic injury, retinal hemorrhage, facial nerve injury)● Intracranial hemorrhage or subgaleal hemorrhage● Hypotension requiring pressor support

Secondary Outcomes

● Secondary outcomes○ Maternal morbidity

• Cesarean delivery • Operative vaginal delivery• 3rd/4th degree perineal lacerations• Infection• Postpartum hemorrhage

○ NICU admissions○ Utilization of health care resources○ Patient-reported outcomes (control of experience, pain)

Power Analysis - Primary Perinatal Outcome

Expectant management group: 3.5%

Effect size: 40%

Power: 80%

Sample size = 3000 per group

Recruitment completed August 2017

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