Transcript Slide 1

C-Section Deliveries
Influencing Late Preterm
Births & The Sequelae of
Late Preterm Deliveries
Heather Brumberg, MD, MPH, FAAP
Medical Director, LHVPN
Assistant Professor of Pediatrics and Clinical Public Health, NYMC
Director of Regional Neonatal Public Health Programs, Maria Fareri
Children’s Hospital, Valhalla, NY
January 22, 2008
Shift in gestational distribution:
May be in part due to change in practice to
deliver earlier to avoid post-term births
2003
1992
Davidoff, MJ et al. Semin Perinatol 30(1):8-15, 2006
Over 70% of All Preterm Births Are
Late Preterm
(34-36 weeks gestation)
34-36 wks
32-33 wks
<32 wks
http://www.marchofdimes.com/files/MP_Late_Preterm_Birth-Every_Week_Matters_3-24-06.pdf
Late Preterms Increasing Over Time
Late Preterms Increasing by
Race/Ethnicity Over Time
Late Preterm Birth Rates and
Economic Burden
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1 out of 11 births is a late preterm infant
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In 2005, prematurity cost the United States
$26.2 billion dollars
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In California,1996- preventing non-medically
indicated births between 34-37 weeks could have
saved 49.9 million dollars
Raju, T. Clin Perinatol 33: 751-763, 2006
Why are Late Preterm Births on the Rise?
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C-section rate is increasing in the late preterm
population
Extremes in maternal age (<16, >35) linked to
premature birth
Assisted reproduction
Obesity/fetal macrosomia
Other maternal medical issues (i.e. preeclampsia)
Reduction in late preterm stillbirths
(Hankins and Longo, 2006; Raju, 2006)
C-Sections Increase Over Time by
Gestational Age
Elective Delivery
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ACOG recommends elective delivery should not be
preformed prior to 39 wks
However, inaccuracies in dating can occur
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Early u/s standard, last menstrual period less accurate
May not always utilized depending on timing of prenatal care
 Has also been implicated in increased preterm birth
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Fetal lung maturity is suggested if dating is unclear
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However, not always done due to perception of risks
due to amniocentesis
Little data, directly link c/s at maternal request (4-18% of all
c-sections) to late preterm birth, although both rates have
risen concurrently
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(Raju, 2006; Jain and Dudell, 2006; Fuchs and Wapner 2006)
Complications of Pregnancy as
Potential Causes
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Preterm labor on the rise in late preterms
Premature rupture of membranes also on the rise
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Expeditious delivery after 34 wks recommended
Standard OB management of these: tocolysis and
glucocorticoids up to 34 wks
Similarly expert opinion recommends intervention for
mild preeclampsia at 37 wks and severe as early as 34
weeks
Beyond 34 wks, aggressive efforts to prevent delivery are
not attempted
(Dobak and Gardner, 2006; Fuchs and Wapner, 2006)
Diabetes and Pregnancy Weight
Gain (Risks for C-Sections and
Preeclampsia) Increased Over Time
Maternal Age (Risk for
Preeclampsia) Increased Over Time
Multiple Gestation Rates Stable, BUT High
Proportion are Increasingly Late Preterms
(6x More Likely to be Premature)
May be due to medical intervention for
maternal (preeclampsia) or fetal reasons
Preeclampsia
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Preeclampsia on the rise (6-10% of all pregnancies),
likely due to change in demographic of pregnant
women
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Increased nulliparity, maternal age, obesity, and multiple
gestations
However, better management has led to reduced maternal
and perinatal complications
Studies did not delineate if delivery of mothers with
preeclampsia was for fetal indication, preterm labor or
rupture of membranes, or preeclampsia
Interestingly, despite ACOG guidelines, 15% of mild
preeclampsia are delivered at 34-36 wks
(Sibai, 2006)
Objective
To identify maternal risk factors associated
with delivery of late preterm infants
(34 - 36 weeks gestation)
Jessica L. Kalia, DO, Paul Visintainer, PhD,
Jordan Kase, MD, Heather L. Brumberg,
MD, MPH E-PAS2007:61:8075.6
Methods
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Birth certificate data from NY State Department of Health Vital
Statistics
Study subjects
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Data analysis
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Term (37-42 weeks gestation) infants
Late preterm (34-36 weeks gestation) infants
Born in Westchester County, New York
2004-2005
Compared late preterm to term infants for delivery characteristics, receipt
of prenatal care, and maternal demographics
Statistical Analysis
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Chi square was used to compare frequencies
Poisson regression was used for analysis of relative risks
Statistical significance set at p < 0.05
Results: Westchester County Live Births by
Weeks Gestation
Late Preterms (8%)
Late Preterms (8%)
term
34-36
32-33
<32
unkn
2004
2005
(n=12,306)
(n=12,860)
Increased C-sections in Late Preterm Infants
80%
% Live Births
60%
*
*
34-36 wks
40%
37-42 wks
20%
0%
C-Section
Vaginal delivery
Total: 25,166 live births
* p< 0.05
% Live Births
More C-Sections in Late Preterm Infants
for Maternal Conditions Related to
Pregnancy
12%
34-36 wk
10%
37-42 wk
8%
*
6%
4%
2%
0%
Elective
Fetal risk
Maternal- preg
related
Maternal- not
preg related
Total: 25,166 live births
* p< 0.05
No Difference in Commencement of
Prenatal Care
Percent Live Births
80%
34-36 weeks
60%
37-42 weeks
40%
20%
0%
1st Trimester
3rd Trimester
or No PNC
Total: 25,166 live births
Extremes of Maternal Age Have
Higher Rates of Late Preterm
Infants
% Live
Births
*
% Live
Births
30%
0.8%
0.6%
34-36 wk
28%
0.4%
37-42 wk
26%
0.2%
24%
0.0%
22%
< 17 yrs old
Total: 25,166 live births
*
≥ 35 years old
* p < 0.05
No Difference in Medicaid Use
40%
34-36 weeks
30%
37- 42 weeks
20%
medicaid primary
Summary of Relative Risks for Late Preterm Infants
Relative Risk
Conclusions
Late preterm delivery more likely at extremes of
maternal age
 Maternal conditions related to pregnancy more likely
to result in c-section delivery of late preterm infant
 C-section delivery more likely in late preterms
 Elective c-section rates are not significantly different
between term and late preterms
 No difference in commencement of prenatal care
between term and late preterms
 No socioeconomic difference in late preterm and
term mothers as measured by primary medicaid use
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Morbidity & Mortality
Morbidities
Total Mortality
Singleton Live Births
RR (95% CI)
Temp Instability
Hypoglycemia
IV Fluid
Term
Late Preterm
RDS
United States
Canada
2.9 (2.8-3.0)
4.5 (4.0-5.0)
Jaundice
0%
10% 20% 30% 40% 50% 60%
Wang M et al Pediatrics 114: 372-376, 2004
Neu J, Semin Perinatol. 30: 77-80, 2006
Raju, T et al. Pediatrics 118: 1207-21, 2006
Kramer, MS et al, JAMA 284: 843-849, 2000
Infant Mortality
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Late preterms 3 times more likely to die than
term infants in their first year of life
Late preterms 6 times as likely to die than term
babies in their first week of life (early neonatal
period)
Late preterms 3 times as likely to die than term
babies after their first week to 27 days (late
neonatal period)
Leading cause is congential anomalies
(Tomashek et al. 2007)
Other Outcomes
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Increased risk of rehospitalization, most
commonly due to jaundice (63%) and infection
(13%; Shapiro-Mendoza et al. 2006)
Increased risk of SIDS 1.37 per 1,000 live births
(33-36 wks) vs. 0.69 per 1,000 live births (term)
as well as increased risk of apnea and apparent
life threatening events (Clapp 2006)
Suck-swallow immaturity and slow
motility/gastric emptying also leads to
prolonged hospitalization and readmission (Neu
2006)
Kinney HC. Seminars in Perinatology 30: 81-88, 2006.
Neurodevelopmental Outcomes
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More likely to have developmental delay by 3 y/o RR
(95%CI)= 1.46 (1.42-1.50)
More likely to be referred for special needs, special
education, and have problems with school readiness
than term counterparts
Small studies also suggest higher risk of cerebral palsy,
speech disorders, behavioral abnormalities
Increased risk of hyberbilirubinemia (jaundice) and
kernicterus
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Abnormal movements, hearing impairment, spasticity,
abnormal movement of eyes
(Engle, 2007; Adams-Chapman, 2006)
Objective
Compare the enrollment in EI and the utilization
of therapeutic services between moderately
preterm (32-36 weeks gestation) and very
preterm (<32 weeks gestation) infants at 12
months ± 2 months corrected age
Jessica L. Kalia DO, Paul Visintainer PhD,
Heather L. Brumberg MD, MPH, Maria Pici
MD, Jordan Kase MD E-
PAS2007:61:6280.25
Why Early Intervention?
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Used as a surrogate to assess neurodevelopment
Objective measurement
33% delay in at least 1 area of development
Must be receiving services, not just referred for
EI evaluation
Methods
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Preterm infants followed at the Regional Neonatal
Follow-up Clinic in White Plains, NY from Jan 2005
through Oct 2006
Included all patients <37 weeks gestation who had an
evaluation at 12 months ± 2 months corrected age (CA)
Stratified into moderately preterm (32-36 weeks
gestation) and very preterm (<32 weeks gestation)
groups
Antenatal, maternal, and neonatal variables obtained by
NICU discharge summaries and parental report
Logistic regression, Chi square, and Fisher’s exact tests
used for analysis
Results
497 preterms
(<37 wks)
n = 169
n = 328
Evaluated
at 12 mo ± 2 mo CA
Not evaluated
at 12 mo ± 2 mo CA
n = 77
n = 92
VP (<32 wks)
MP (32-36 wks)
n = 208
n = 101
Not 12 mo ± 2 mo CA
at time of study
Lost to follow up
n = 19
Not assessed at
12 mo ± 2 mo CA
Patient Characteristics
Gestational age (weeks) #
Birth wt (grams) #
Length of stay (weeks) #
5 min Apgar ^
Moderately
Preterm
Very
Preterm
34 ± 1
28 ± 2
<0.001
2124 ± 493
1114 ± 374
<0.001
2.3 ± 2.0
8.9 ± 5.4
<0.001
9 (6,9)
7 (1,9)
<0.001
Sex, n (%)
p value
NS
Male
55 (60)
37 (48)
Female
37 (40)
40 (52)
Delivery type, n (%)
NS
NSVD
27 (32)
20 (26)
C/S
40 (48)
39 (51)
Stat C/S
17 (20)
18 (23)
#
mean ± SD , ^median (min,max), NS = not significant
Patient Demographics
Moderately
Preterm
Very
Preterm
Multiple gestation, n (%)
p value
0.02
Singleton
62 (67)
60 (78)
Twins
21 (22)
17 (22)
Triplets
9 (10)
0 (0)
Medicaid, n (%)
80 (87)
71(92)
NS
Maternal age (years) #
31 ± 7
29 ± 7
NS
Maternal race, n (%)
0.01
Caucasian
34 (38)
14 (18)
African American
20 (22)
21 (28)
Hispanic
30 (33)
26 (34)
6 (7)
15 (20)
8 (9)
7 (9)
Other
Maternal substance abuse, n (%)
#
NS
mean ± SD , NS = not significant
Rate of Therapy Use
80%
*
70%
*
60%
50%
40%
*
MP
*
30%
*
20%
10%
0%
EI
* p= <0.05
PT
OT
Speech
Special
Ed
VP
Very Preterm vs. Moderately Preterm
Odds Ratios
EI
PT
OT
*
Speech
Special
Ed
0
1
10
Very Preterm vs. Moderately Preterm
Adjusted Odds Ratios
EI
Adjusted for:
PT
5 minute Apgar score
Caffeine
OT
BPD
RDS
Speech
Length of stay
Special
Ed
0
1
10
Summary
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Over 1/3 of moderately preterm infants were
enrolled in EI and 28% received physical
therapy
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When adjusting the odds ratios for neonatal
factors, there was no difference in the odds of
utilizing therapies between the two gestational
age groups
Conclusion
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Moderately preterm babies are at risk and must
be screened and referred for interventional
therapies
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They should not be considered “small” full term
infants
Implications
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If our results could be extrapolated to the general
population, there would be 150,000 moderately
preterm and 75,000 very preterm infants enrolled
in EI per year
Acknowlegements
Westchester Medical Center
Jordan Kase MD
Jessica Kalia, DO
Sergio Golombek MD, MPH
Dept of Epidemiology, NY
Medical College
Paul Visintainer PhD
Children’s Rehabilitation Center
Maria Pici MD
NY State Department of Vital
Statistics
-Larry Schoen, Director of
the Statistical Analysis and
Program Support Unit in the
Bureau of Biometrics and
Health Statistics
-Daljit Singh, Biostatistician
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