Data by: Reese H. Clark, M.D.
Presented by: Bryan L. Ohning, M.D., Ph.D.
From the March of Dimes Web Site:
http://www.marchofdimes.com/peristats
 In 2005, 1 in 8 babies (12.7% of live births) were born preterm
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in the United States.
Between 1995 and 2005, the rate of infants born preterm in the
United States increased more than 15%.
The preterm birth rate in the United States is highest for black
infants (18.1%), followed by Native Americans (13.8%),
Hispanics (12.0%), whites (11.5%) and Asians (10.5%).
In 2005, compared with singleton births (one baby), multiple
births in the United States were about 6 times as likely to be
preterm.
Between 1996 and 2004 there was an increase of nearly 60,000
singleton preterm births. 92 percent of those infants were
delivered by a cesarean section.
From the March of Dimes Web Site:
http://www.marchofdimes.com/peristats
 Following three decades of increases in our nation, in 2008 we
saw the first two-year decline in the preterm birth rate, a 4
percent drop from 2006.
 The 2008 preliminary preterm birth rate dropped to 12.3
percent, from the 2006 final rate of 12.8 percent.
 The March of Dimes says 79 percent of the decline
was among babies born just a few weeks too soon.
 Overall, the United States received a "D" on the report card,
when national preterm birth rates are measured against the
Healthy People 2010 goals.
 The United States has a high rate of preterm birth compared
to most industrialized countries.
From the March of Dimes Web Site:
http://www.marchofdimes.com/peristats
 In 2005, the annual societal economic cost
(medical, educational, and lost productivity)
associated with preterm birth in the United States
totaled to be at least……
26.2 billion dollars!
http://www.marchofdimes.com/peristats
http://www.marchofdimes.com/peristats
http://www.marchofdimes.com/peristats
Optimizing Care and Outcome for Late-Preterm (Near-Term)
Infants. Raju et al. Pediatrics 2006;118;1207-1214
 The American Academy of Pediatrics and the
American College of Obstetricians and Gynecologists
define a “preterm” infant as one who is born before
the end of the 37th week (259th day) of pregnancy,
counting from the first day of the last menstrual
period.
 Various subsets of preterm infants between 33 weeks
and term have been described as “marginally
preterm,” “moderately preterm,” “minimally
preterm,” and “mildly preterm”.
Optimizing Care and Outcome for Late-Preterm (Near-Term)
Infants. Raju et al. Pediatrics 2006;118;1207-1214
 The panel suggested designating infants born
between the gestational ages of 34 0/7 weeks
through 36 6/7 weeks as “Late Preterm” and
discontinue the use of the phrase “near term.”
 The panel was of the opinion that “near term” can be
misleading, conveying an impression that these infants are
“almost term,” resulting in underestimation of risk and lessdiligent evaluation, monitoring, and follow-up.
 The panel confirmed that gestational age should be rounded
off to the nearest completed week, not to the following
week. Thus, an infant born on the 5th day of the 36th week
(35 weeks and 5/7 days) is at a gestational age of 35 weeks,
not 36 weeks.
C-Section
Deliveries by C-Section
35%
30%
25%
20%
15%
10%
5%
0%
Csection
2010
2008
2006
http://www.cdc.gov/nchs/VitalStats.htm
2004
2002
2000
1998
1996
1994
Year
http://www.marchofdimes.com/peristats
2000
2008
Percent of Births
60%
50%
40%
30%
20%
10%
CDC web site -- http://205.207.175.93/VitalStats/ReportFolders/reportFolders.aspx
42 and over
Birth Weight Group
41
40
37-39
36
32-35
28-31
20-27
0%
Gestational Age of NICU Patients
1998
2008
2010
Percent of Discharges
14%
12%
10%
8%
6%
4%
2%
0%
>42
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
Estimated Gestational Age
Raju et al. Pediatrics 2006;118;1207-1214
 Factors that potentially are contributing to increasing
preterm births in the United States
 Increasing proportion of pregnant women >35
years of age
 Multiple births
 Medically indicated deliveries secondary to better
surveillance of the mother and the fetus
 Attempts to reduce stillbirths
Mortality of Late-Preterm (Near-Term) Newborns in Utah
Young P et al. Pediatrics 2007;119;659-665
Number of Births
NICU Admissions:
120000
100000
80000
60000
40000
20000
0
34
35
36
37
38
39
Gestational Age
40
41
42
Mortality of Late-Preterm (Near-Term) Newborns in Utah
Young P et al. Pediatrics 2007;119;659-665
Neonatal (<=28d) Mortality/1000
Risk
20
15
10
5
0
34
35
36
37
38
39
Gestational Age
40
41
42
Infant Mortality Per 1000
Live Births
2007
2005
2003
2001
20
15
10
5
0
32–33
34–36
37–38
39–41
Estimated Gestational Age Group
Infant Mortality Rate is the number of Infant deaths per 1000 live births
http://205.207.175.93/VitalStats/TableViewer/tableView.aspx?ReportId=3274
42 weeks
Are C/Sections safer than Vaginal Delivery ?
2003-2006 Data
Infant Deaths/1000 Live
Births
Death Rate Csection Delivery
Death Rate Vaginal Delivery
25
20
15
10
5
0
32-33 weeks
34-36 weeks
37-39 weeks
40 weeks
Estimated Gestational Age Group
http://wonder.cdc.gov/lbd.html
41 weeks
Maternal mortality and severe morbidity associated with low-risk
planned cesarean delivery versus planned vaginal delivery at term.
Liu S et al. CMAJ. 2007;176:455-460.
 Canadian Institute for Health Information's Discharge
Abstract Database
 Retrospective population-based cohort study of all
women in Canada (excluding Quebec and Manitoba) who
delivered from April 1991 through March 2005.
 Healthy women who underwent a primary cesarean
delivery for breech presentation constituted a surrogate
"planned cesarean group" considered to have undergone
low-risk elective cesarean delivery, for comparison with
an otherwise similar group of women who had planned
to deliver vaginally, the “planned vaginal delivery group”.
Maternal mortality and severe morbidity associated with low-risk
planned cesarean delivery versus planned vaginal delivery at term.
Liu S et al. CMAJ. 2007;176:455-460.
 Caesareans group had an overall rate of morbidity of
27.3 per 1000 deliveries compared to 9.0 per 1000
planned vaginal deliveries.
 Cesarean group had increased postpartum risks of:
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cardiac arrest (OR 5.1, 95% CI 4.1–6.3)
wound hematoma (OR 5.1, 95% CI 4.6–5.5),
hysterectomy (OR 3.2, 95% CI 2.2–4.8)
major puerperal infection (OR 3.0, 95% CI 2.7–3.4)
anesthetic complications (OR 2.3, 95% CI 2.0–2.6)
venous thromboembolism (OR 2.2, 95% CI 1.5–3.2)
hemorrhage requiring hysterectomy (OR 2.1, 95% CI 1.2–3.8)
and stayed in hospital longer (adjusted mean difference 1.47 d, 95% CI
1.46–1.49 d)
 A limitation of this study: women with severe health conditions
are more likely to pre-schedule births by caesarean.
Original Article
Timing of Elective Repeat Cesarean Delivery
at Term and Neonatal Outcomes
Alan T.N. Tita, M.D., Ph.D., Mark B. Landon, M.D., Catherine Y. Spong, M.D., Yinglei
Lai, Ph.D., Kenneth J. Leveno, M.D., Michael W. Varner, M.D., Atef H. Moawad, M.D.,
Steve N. Caritis, M.D., Paul J. Meis, M.D., Ronald J. Wapner, M.D., Yoram Sorokin,
M.D., Menachem Miodovnik, M.D., Marshall Carpenter, M.D., Alan M. Peaceman,
M.D., Mary J. O'Sullivan, M.D., Baha M. Sibai, M.D., Oded Langer, M.D., John M.
Thorp, M.D., Susan M. Ramin, M.D., Brian M. Mercer, M.D., for the Eunice Kennedy
Shriver NICHD Maternal–Fetal Medicine Units Network
N Engl J Med
Volume 360(2):111-120
January 8, 2009
Study Overview
• Among a large cohort of women with singleton
pregnancies who underwent elective repeat
cesarean sections, more than a third of deliveries
were performed before 39 weeks of gestation
• Compared with deliveries at or after 39 weeks,
deliveries before 39 weeks of gestation (even those
during the last 3 days before week 39) were associated with
an increased risk of a composite primary outcome
that included neonatal death, respiratory
complications, need for mechanical ventilation,
treated hypoglycemia, newborn sepsis, and
admission to the neonatal intensive care unit.
Proportion of Patients At Each EGA
(Data Based on 434,665 NICU infants where Respiratory Support Type Was Reported, 1997-2008)
Proportion of Patients
RA
Oxygen
CPAP
Vent
HFV
100%
80%
60%
40%
20%
0%
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
Estimated Gestational Age
Reese H. Clark, MD
The Near-Term Respiratory Failure Research Group
Journal of Perinatology 2005; 25:251–257
Study Population
 Inclusion criteria
 ≥34 weeks’ EGA
 Intubated 72 hours and expected to need ventilation for
≥6 hours
 Parental consent
 Delivery service available
 Ability to refer for extracorporeal membrane oxygenation
(ECMO)
 Exclusion criteria
 Not on ventilator
 No delivery service
Endpoints
 Death
 Oxygen support at discharge or 30 days, whichever comes
first
 Brain injury
 Intracranial hemorrhage
 Seizures requiring treatment until discharge
 Brain atrophy or stroke
Demographics
(1011 patients enrolled)
 EGA (weeks)
 Birth weight (kg)
 Maternal age (years)
 Median Apgars @ 1/5
 Male gender
 Antenatal steroids
37 ± 2
3 ± 0.6
28 ± 6
7/8
622 (62%)
91 (9%)
Demographics
 Race
 Black
 Hispanic
 White
116 (12%)
147 (15%)
687 (69%)
 Delivery
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Vaginal delivery
Elective Cesarean section
Emergent Cesarean section
Forceps extraction
Vacuum extraction
408 (41%)
229 (23%)
324 (32%)
20 (2%)
30 (3%)
Outcomes
 Of the 1011 patients enrolled:
 51 (5%) died
 Deceleration of care
 Other cause of death
 Progressive respiratory failure
 Renal failure
 Major congenital anomaly
8
5
11
4
23
 73 (7.2%) patients met ECMO criteria and 36 (3.6%, 49%)
were treated with ECMO
 73 (7.2%) died or were treated with ECMO
Causes of Death
Deceleration of care
Other
Respiratory failure
Renal failure
Congenital anomaly
Occurrence of
Chronic Lung Disease
 109/1011 (10%) had a diagnosis of chronic lung disease
and 17 (16%) of these 106 were on a ventilator at 30 days
or discharge
 77/945 (8%) of survivors went home on oxygen
Outcomes
 Median ventilator days in survivors was 3 (1-5
quartiles) and in non-survivors was 5 (3-15 quartiles)
 Median age at discharge for survivors (LOS) was 13
days (9-21 quartiles)
 Median age at death was 7 days (2-27 quartiles)
 86/1011 (9%) had a report of a neurological
complication
Short-term outcomes of infants born at 35 and 36 weeks
gestation: We need to ask more questions.
Escobar GJ, et al. Semin Perinatol. 2006;30:28-33.
 Newborns born at 35 and 36 weeks gestation
experienced considerable mortality and morbidity.
 Approximately 8% required supplemental oxygen support
for at least 1 hour, almost 3 times the rate found in infants
born at > or =37 weeks.
 Following discharge from the birth hospitalization, 35 to 36
week infants were much more likely to be re-hospitalized
than term infants, and this increase was evident both
within 14 days as well as within 15 to 182 days after
discharge.
 Had more problems with hyperbilirubinemia
School outcomes of late preterm infants: special needs and
challenges for infants born at 32 to 36 weeks gestation.
Chyi LJ et al. J Pediatr 2008;153:25-31.
 Examined school outcomes from kindergarten to grade 5 of
infants born at 32 weeks to 36 weeks’ gestation.
 When compared with a large group (n = 13,671) of term
infants followed in the Early Childhood Longitudinal StudyKindergarten Cohort (ECLS-K), late preterm infants (n = 767)
had lower reading and math scores than their term
counterparts in 1st grade.
 Late preterm infants also had higher participation in special
education during early grades and higher odds for belowaverage reading skills in all grades, although there was
resolution of test score differences by the 3rd and 5th grade.
Late preterm infants have worse 24-month
neurodevelopmental outcomes than term infants.
Woythaler MA, McCormick MC, Smith VC. Pediatrics 2011; 127: e622-e629.
 BACKGROUND: Late preterm infants (34-37 weeks' gestation)
are often perceived at similar risks for morbidity and mortality
as term infants.
 OBJECTIVE: To compare the neurodevelopmental outcomes of
late preterm to term infants.
 METHODS: Study sample of 6300 term and 1200 late preterm
infants came from the Early Childhood Longitudinal StudyBirth Cohort. General estimating equations were used to get
weighted odds of having developmental delay, mental index
scores (MDI) or psychomotor index scores (PDI) < 70, at 24
months of age.
Late preterm infants have worse 24-month
neurodevelopmental outcomes than term infants.
Woythaler MA, McCormick MC, Smith VC. Pediatrics 2011; 127: e622-e629.
 Late preterm infants compared with term infants had lower
MDI (85 vs 89) and PDI (88 vs 92), both P < .0001, respectively.
 A higher proportion of late preterm infants compared with
term infants had an MDI <70 (21% vs 16%; P < .0001).
 After controlling for statistically significant and clinically
relevant descriptive characteristics, late preterm infants still
had higher odds of mental developmental delay (odds ratio:
1.52 [95% confidence interval: 1.26-1.82] or physical
developmental delay (odds ratio: 1.56 [95% confidence
interval: 1.30-1.89]).
Late-preterm birth and its association with cognitive and
socioemotional outcomes at 6 years of age.
Talge NM, Holzman C, Wang J, Lucia V, Gardiner J, Breslau N. Pediatrics.
2010;126:1124-1131.
 Data came from a study of low- and normal-weight births
sampled from urban and suburban settings between 1983
and 1985 (low birth weight, n = 473; normal birth weight;
n = 350).
 Random sampling was used to pair singletons born latepreterm with a term counterpart whose birth weight z
score was within 0.1 SD of his or her match (n = 168
pairs). With random-effects models, we evaluated
whether pairs differed in their IQ scores and teacherreported behavioral problems at the age of 6 years.
Late-preterm birth and its association with cognitive and
socioemotional outcomes at 6 years of age.
Talge NM, Holzman C, Wang J, Lucia V, Gardiner J, Breslau N. Pediatrics.
2010;126:1124-1131
 In adjusted models, late-preterm birth was associated with an
increased risk of full-scale (adjusted odds ratio [aOR]: 2.35 [95%
confidence interval (CI): 1.20-4.61]) and performance (aOR: 2.04
[95% CI: 1.09-3.82]) IQ scores below 85.
 Late-preterm birth was associated with higher levels of internalizing
and attention problems, findings that were replicated in models that
used thresholds marking borderline or clinically significant problems
(aOR: 2.35 [95% CI: 1.28-4.32] and 1.76 [95% CI: 1.04-3.0],
respectively).
 CONCLUSIONS: Late-preterm birth is associated with behavioral
problems and lower IQ at the age of 6, independent of maternal
IQ, residential setting, and sociodemographics.
Dr Jain’s Comments
 What is most striking about these observations is that the
late preterm infants included in the study were
presumably healthy, had no reported “neonatal
compromise,” and would have been completely missed
even if neurologic follow-up and early intervention
programs were in place for high-risk infants
The “Late Preterm” Infant
To Summarize:
 Frequently require NICU admission
 More medical interventions needed
 Longer Length of Stay
 Much higher costs
 Higher mortality
 Worse Neurodevelopmental Outcomes