Complications of Delivery
Before 39 Weeks:
OB Perspective
Roger B. Newman MD
Maas Endowed Chair For Reproductive Sciences
Professor and Vice-Chairman
Department of Ob-Gyn
Medical University of South Carolina
Complications of Delivery <39 Wks
Learning Objectives
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Rates of late-preterm birth in US
Reasons for the increase
Indications/contraindications for IOL
Advantages/disadvantages of IOL
Recommendations
Preterm Birth in US
• Has increased 20% in past 15 years: 10.6% in
1990 to 12.7% in 2005
• “Late-Preterm” (34-36 weeks) increasing at a
greater rate than other PTB subgroups
• “Late-Preterm” birth rate was 7.3% in 1990 vs
9.1% in 2005; 25% increase
Delivery Indications:
Late- Preterm Births
• 292,627 late-preterm births in 2001: US Birth
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Cohort Linked Birth / Death Files (singletons)
76.8% had maternal/fetal indication or
spontaneous labor; 23.2% (67.909) no recorded
indication
No recorded indication associated with: older age,
non-Hispanic white, ≥ 13 yrs of education,
multiparity, southern, midwest, or western region,
or prior child ≥ 4000 g birth weight
Reddy et al, Pediatrics 2009
Induction of Labor
United States
• Doubled from ’90 to ’06: 9.5% to 22.5%
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Some for medical/Ob indications
Most: marginal or elective
Why?
Better cervical ripening agents
Patient/MD convenience
Relaxed attitudes re: marginal indications
Concerns re: fetal death with expect Rx
CDC 2009; Rayburn, AJOG 2002; Moore, Clin Ob-Gyn 2006
Accuracy of Vital Statistic Data
Birth Certificates
• Ohio Perinatal Quality Collaborative 2008
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20 Ohio hospitals
To decrease nonmedically-indicated scheduled
deliveries
All scheduled deliveries: 36-38 6/7 wks
Comparison of chart abstraction vs birth certificates
11% in BC vs 1% in chart
Birth Certificate Data vs Chart
Abstracted Data
Bailit; Induction rates derived from birth certificate data. Am J Obstet Gynecol 2010
Conceptual Diagram
Timing of Indicated LatePreterm and Early-Term Birth
• Workshop Feb. 2011, sponsored by Eunice
Kennedy Shriver NICHD and SMFM
• Synthesize available evidence regarding
conditions resulting in medically-indicated
late-preterm or early-term births
• Based on available data and expert opinion,
optimal timing for delivery was determined by
consensus
Spong, Mercer, D’Alton et al OBGYN, 2011
Induction of Labor
Contraindications
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Prior classical CS
Prior transmural uterine incision
Placenta or vasa previa
Umbilical cord prolapse
Transverse lie
Induction of Labor
Disadvantages
• Increased Cesarean rate
• Iatrogenic prematurity
• Cost
Induction of Labor
37-38 wks vs ≥39 wks
• Prospective observational study
18,000 deliveries in 27 HCA hospitals
3 month epoch in 2007
• Planned elective IOL: 31% of all deliveries
• Population
790 at 37-38 wks (28.3%)
2004 at ≥39 wks (71.7%)
Clark, AJOG, 2009
Induction of Labor
37-38 wks vs ≥39 wks
• Results: higher NICU adm (7.7 vs 3.0%)
• Cesarean rates correlated with cx
dilatation in both nullips and multips
• Term should no longer be 37 wks
Clark, AJOG, 2009
Induction of Labor
Nulliparity
• Matched cohort of nullips, singleton, ceph
• Population: Belgium
7683: elective IOL
7683: spontaneous labor
• 38-41 weeks
• BW 3000-4000gms
• Cervical status and ripening not known
Cammu, AJOG 2002
Induction of Labor
Nulliparity
• Higher Cesarean: 10 vs 7% (1st stage problems)
• Higher instrumental delivery: 32 vs 29%
• More epidurals: 80 vs 58%
• More NICU: 11 vs 9%
• Nullips should be informed before elective IOL
Cammu, AJOG 2002
Induction of Labor
Nulliparity
• Retrospective cohort: Tacoma, Wash
• Elective IOL (n=263)
Low risk at 38-41 wks
Compared to spon labor
• Primary outcome: Cesarean OR 2.4, CI 1.2,4.9
• Longer labor (4 hrs) and more cost ($273)
Induction of Labor
Nulliparity
• Multiple cohort studies: Cesarean rate
doubled for elective and medical inductions
• Primarily due to unfav cervix: Bishop ≤5
• RPT showed no diff in Cesarean with
favorable cx (Bishop ≥ 5)
Nielsen, J Mat Fet Neo Med 2005
Bishop’s Score
Score
0
1
2
3
Dilatation
closed
1-2 cm
3-4 cm
5+ cm
Effacement
0 – 30%
40 -50%
60 -70%
80+%
Station
-3
-2
-1,0
+1,+2
Position
posterior
mid-position
anterior
Consistency
firm
moderately firm
Soft
A point is added: Preeclampsia/Each prior vaginal delivery
A point is subtracted: Postdates/Nulliparity/pPROM
Cesarean Rates
BS 0 - 3
BS 4 – 6
BS 7 - 10
First Time Mothers
45%
10%
1.4%
Women with Past Vaginal Deliveries
7.7%
3.9%
0 .9%
Bishop’s Score
Induction of Labor
Nulliparity
• Retrospective cohort: Northwestern
• Elective IOL (n=294)
Nullip
Bishop ≥ 5
39-40 5/7 wks
Compared to expectantly managed
• Primary Outcome: Cesarean ( 21 vs 20%)
• IOL: longer labor (13 vs 9 hrs)
Osmundson, ObstetGynecol, 2010
Induction of Labor
Multiparas
• No increased Cesarean rate
• Most data retrospective, but one small PRT
• Large population-based cohort
1775 low risk multips at term IOL vs
5785 similar pts with spon labor
Cervical ripening agents if unripe
Cesarean similar: 3.8 vs 3.6% (RR 1.07)
Nielsen, J Mat Fet Neo Med 2005; Dublin, AJOG 2000
Induction of Labor
Respiratory Morbidity
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33,289 deliveries ≥ 37 wks
RDS or TTN requiring adm to NICU
Comparison with overall baseline term rates
Elective induction at term with vag deliv
37-37 6/7: 12.6/1000, OR 2.5, CI 1.5-4.22
38-38 6/7: 7.0/1000, OR 1.4, CI 0.8-2.2
39-39 6/7: 3.2/1000, OR 0.6, CI 0.4-1.0
Morrison, BJOG, 1995
Induction of Labor
Respiratory Morbidity
• Same comparison in failed IOL/Cesarean
37-37 6/7: 57.7/1000, OR 11.2, CI 5.4-13.1
38-38 6/7: 9.4/1000, OR 1.8, CI 0.6-5.9
39-39 6/7: 16.2/1000, OR 3.2, CI 1.4-7.4
• Elective delivery by Cesarean without labor:
Increased freq at all gestational ages
Morrison, BJOG 1995
Timing of Elective Repeat
Cesarean
• MFMU Network: secondary analysis of
Cesarean registry
• 19 academic centers 1999-2002
• N=13,258 for elective term repeat Cesarean
37 wks: 6.3%
38 wks: 29.5%
39 wks: 49.1%
Tita, NEJM, 2009
Timing of Elective Repeat
Cesarean
• Composite outcome: respiratory, sepsis,
hypoglycemia, NICU admit, death
37wks: 15.3%, OR 2.1, CI 1.7-2.5
38 wks: 11.0%, OR 1.5, CI 1.3-1.7
39 wks: 8.0%
• Individual outcomes also signif different
• No diff between 39 and 40 wks
• Increased morbidity at 41 wks
Tita, NEJM
2009
Elective Repeat Cesarean Delivery &
Incidence of Primary Outcome
Timing of Elective Repeat
Cesarean
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2-3 stillbirths avoided with delivery < 39 wks
176 extra cases of primary outcome
145 extra admissions to NICU
63 extra cases of RDS
Also increased morbidity 38 4/7-38 6/7
Tita, NEJM 2009
Neonatal Morbidity
Elective Cesarean
• Elective Cesarean at term: breech,
social, CPD, repeat, fundal scar
• Amsterdam ’94-’98: n=324
• Decreased respiratory morbidity with
advancing gest age (p<0.05)
37-37 6/7 wks: 8.4%
38-38 6/7wks:
4.4%
39+ wks:
1.8%
van den Berg, EJOG, 2001
Economic Consequences
Decision Analysis
• Cohort of 100,000 patients
Induction at 39, 40, 41 wks vs expectant Rx
All patients delivered by 42 wks
• IOL at 39 weeks
12,000 excess Cesareans
Additional cost: $100 million
133 fetal deaths avoided
Regardless of cx ripeness or parity
Kaufman, AJOG, 2002
Decision Analysis
• IOL less expensive
Later gestational ages
Multips
Favorable cervix
• Most costly
Nullips with unfavorable cervix
Cost halved with favorable cervix (Bishop > 5)
Still overall added expense
Kaufman, AJOG, 2002
Induction of Labor
Bottom Line
• No evidence for elective IOL
• Need large randomized studies
Maternal and neonatal safety
Reduced unexplained fetal death
Cost-effectiveness
Complications of Delivery <39 Wks
Final Thoughts
• IOL only if continuing preg has greater
maternal/fetal risks than the intervention
• No elective IOL at term without indications
Increased Cesarean rate
Iatrogenic prematurity
Increased cost
No proven benefits
• Bishop score best at predicting success
• Elective primary or repeat Cesarean < 39 weeks
inappropriate without indication
• Term should now be considered 39 weeks