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

2. Shift in gestational distribution: May be in part due to change in practice to deliver earlier to avoid post-term births
1992
2003
Davidoff, MJ et al. Semin Perinatol 30(1):8-15, 2006

3. Over 70% of All Preterm Births Are Late Preterm (34-36 weeks gestation)
Prematurity is on the rise in the United States.
In 2003, 12.1% of all live births were preterm births. In 2005, this number increased to 12.5%. Late preterm infants, those babies weeks gestation account for more than 70% of all preterm births.

4. Late Preterms Increasing Over Time

5. Late Preterms Increasing by Race/Ethnicity Over Time

6. Late Preterm Birth Rates and Economic Burden
1 out of 11 births is a late preterm infant
In 2005, prematurity cost the United States $26.2 billion dollars
In California,1996- preventing non-medically indicated births between weeks could have saved 49.9 million dollars
However, the results in California are not generalizable because state and national data are lacking to estimate the proportion of nonindicated (and possibly preventable) preterm births.
Raju, T. Clin Perinatol 33: , 2006

7. Why are Late Preterm Births on the Rise?
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)

8. C-Sections Increase Over Time by Gestational Age

9. Elective Delivery
ACOG recommends elective delivery should not be preformed prior to 39 wks
However, inaccuracies in dating can occur
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
Fetal lung maturity is suggested if dating is unclear
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
(Raju, 2006; Jain and Dudell, 2006; Fuchs and Wapner 2006)

10. Complications of Pregnancy as Potential Causes
Preterm labor on the rise in late preterms
Premature rupture of membranes also on the rise
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)

11. Diabetes and Pregnancy Weight Gain (Risks for C-Sections and Preeclampsia) Increased Over Time

12. Maternal Age (Risk for Preeclampsia) Increased Over Time

13. 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

14. Preeclampsia
Preeclampsia on the rise (6-10% of all pregnancies), likely due to change in demographic of pregnant women
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 wks
(Sibai, 2006)

15. Objective To identify maternal risk factors associated
with delivery of late preterm infants ( weeks gestation)
Jessica L. Kalia, DO, Paul Visintainer, PhD, Jordan Kase, MD, Heather L. Brumberg, MD, MPH E-PAS2007:61:8075.6

16. Methods
Birth certificate data from NY State Department of Health Vital Statistics
Study subjects
Term (37-42 weeks gestation) infants
Late preterm (34-36 weeks gestation) infants
Born in Westchester County, New York
Data analysis
Compared late preterm to term infants for delivery characteristics, receipt of prenatal care, and maternal demographics
Statistical Analysis
Chi square was used to compare frequencies
Poisson regression was used for analysis of relative risks
Statistical significance set at p < 0.05

17. Results: Westchester County Live Births by Weeks Gestation
Late Preterms (8%)
Late Preterms (8%)
2004
(n=12,306)
2005
(n=12,860)

18. Increased C-sections in Late Preterm Infants* *
% Live Births
Total: 25,166 live births
* p< 0.05 *

19. More C-Sections in Late Preterm Infants for Maternal Conditions Related to Pregnancy*
% Live Births
Total: 25,166 live births
* p< 0.05

20. No Difference in Commencement of Prenatal Care
Percent Live Births
Total: 25,166 live births

21. Extremes of Maternal Age Have Higher Rates of Late Preterm Infants
% Live Births *
% Live Births *
Total: 25,166 live births
* p < 0.05

22. No Difference in Medicaid Use

23. Summary of Relative Risks for Late Preterm Infants

24. 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

25. Morbidity & Mortality Morbidities Total Mortality
Singleton Live Births
RR (95% CI)
United States 2.9 ( )
Canada 4.5 ( )
Wang M et al Pediatrics 114: , 2004
Neu J, Semin Perinatol. 30: 77-80, 2006
Raju, T et al. Pediatrics 118: , 2006
Kramer, MS et al, JAMA 284: , 2000

26. Infant Mortality
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)

27. Other Outcomes
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 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)

28. At 34 weeks, the overall brain weight is 65% of term weight
At 34 weeks, the overall brain weight is 65% of term weight. It is possible that ex utero brain growth is different from in utero brain growth. Studies need to be done in this area.
Kinney HC. Seminars in Perinatology 30: , 2006.

29. Neurodevelopmental Outcomes
More likely to have developmental delay by 3 y/o RR (95%CI)= 1.46 ( )
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
Abnormal movements, hearing impairment, spasticity, abnormal movement of eyes
(Engle, 2007; Adams-Chapman, 2006)

30. 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
The goal of our study was to compare at 12 mo ± 2mo corrected age, the enrollment in EI and the utilization of therapeutic services between moderately preterm and very preterm infants. We targeted enrollment in EI because in order for a child to qualify for this service, there must be at least a 33% developmental delay. This is an objective measurement that can be translated across examiners and developmental testing methods. It is important to understand that we looked at enrollment in EI not just babies who were referred for evaluation.
Jessica L. Kalia DO, Paul Visintainer PhD, Heather L. Brumberg MD, MPH, Maria Pici MD, Jordan Kase MD E-PAS2007:61:

31. Why Early Intervention?
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

32. Methods
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
In this retrospective study, our cohort of infants were preterm infants followed at the regional neonatal follow up clinic in White Plains, NY from Jan 2005 to Oct All preterms who had an evaluation at the follow up clinic at 12 mo ± 2mo corrected age were included and then stratified into moderately preterm and very preterm groups. We analyzed antenatal, maternal, and neonatal variables obtained by parental report and NICU discharge summaries.

33. Results
Our dataset contained 497 preterm infants, of which 169 met our inclusion criteria. Of those, 77 were very preterm and 92 were moderately preterm babies were not yet 12 mo +/- 2 mo corrected age at the time of the study. 20% of the preterm babies were lost to follow up. 19 did not have an examination at the clinic during the time window we were studying. Over 65% of the patients we studied were born at Westchester Medical Center. The remainder were born in hospitals throughout the lower Hudson Valley region.

34. Patient Characteristics
Moderately
Preterm
Very Preterm
p value
Gestational age (weeks) #
34 ± 1
28 ± 2
<0.001
Birth wt (grams) #
2124 ± 493
1114 ± 374
Length of stay (weeks) #
2.3 ± 2.0
8.9 ± 5.4
5 min Apgar ^
9 (6,9)
7 (1,9)
Sex, n (%) NS
Male
55 (60)
37 (48)
Female
37 (40)
40 (52)
Delivery type, n (%)
NSVD
27 (32)
20 (26)
C/S
40 (48)
39 (51)
Stat C/S
17 (20)
18 (23)
We looked at various antenatal and neonatal characteristics of the babies included in our study. The very preterm and moderately preterm babies were significantly different from each other in obvious ways such as mean GA , birthweight, length of stay, and 5 minute Apgar score.
# mean ± SD , ^median (min,max), NS = not significant

35. Patient Demographics Moderately Preterm Very Preterm p value
Multiple gestation, n (%)
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
Maternal race, n (%)
0.01
Caucasian
34 (38)
14 (18)
African American
20 (22)
21 (28)
Hispanic
30 (33)
26 (34)
Other
6 (7)
15 (20)
Maternal substance abuse, n (%)
8 (9)
7 (9)
Multiple gestation differs between the moderately preterm and very preterm groups due to the 9 triplets in the moderately preterm group. There are also racial differences between the two groups.
# mean ± SD , NS = not significant

36. Rate of Therapy Use * * * * * p= <0.05 *
From this data, we can see that 36% of MP used EI, 28% used PT, 17% OT, 16% ST and 8% special education. This is a substantial number of services needed by babies considered to be “near” term. We also may be underestimating their use of speech therapy and special education as these services are usually started after 12 months of age.
* p= <0.05

37. Very Preterm vs. Moderately Preterm Odds RatiosEI PT OT
Speech *
Special Ed
When we looked at the unadjusted odds ratios comparing the use of therapies in very preterms to moderately preterms, not surprisingly we found that very preterm infants were more likely to utilize EI, PT, OT, speech therapy and special education. 1 10

38. Very Preterm vs. Moderately Preterm Adjusted Odds RatiosEI
Adjusted for:
5 minute Apgar score
Caffeine
BPD
RDS
Length of stay PT OT
Speech
However, when we adjusted for the neonatal characteristics that were significantly different between the moderately preterm and very preterm infants- the 5 minute Apgar score, caffeine for apnea of prematurity, BPD, RDS, and length of stay there was no significant difference between the likelihood of very preterms and moderately preterms to use EI, PT, OT, speech tx and special education. Perhaps extrauterine brain growth is different than intrauterine, and any degree of prematurity, even moderate prematurity may put babies are at risk for developmental delays.
Special Ed 1 10

39. Summary
Over 1/3 of moderately preterm infants were enrolled in EI and 28% received physical therapy
When adjusting the odds ratios for neonatal factors, there was no difference in the odds of utilizing therapies between the two gestational age groups
We conclude that in our cohort of infants, over 1/3 of the moderately preterm infants were enrolled in EI and 28% received PT. When we adjusted for factors such as the 5 minute Apgar score, caffeine for apnea of prematurity, BPD, RDS and length of stay, there was no difference in the odds of utilizing therapies between moderately preterm and very preterm infants.

40. Conclusion
Moderately preterm babies are at risk and must be screened and referred for interventional therapies
They should not be considered “small” full term infants
Therefore we conclude that moderately preterm babies are at risk for developmental delay and must be screened and referred for interventional therapies. We should not treat them as small full term infants.

41. Implications
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
We speculate that if our results could be extrapolated to the general population, being that there are almost 4.2 million births per year and a 12.5% prematurity rate, there would be 150,000 moderate preterms and 75,000 very preterm infants enrolled in early intervention each year. Quite a few moderately preterm infants! Future studies need to be done on this rapidly growing group of moderately preterm infants. Prospective and longitudinal studies could be done to show developmental, behavioral, cognitive, psychomotor and medical outcomes of these at risk infants. Thank you.

42. 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

43. Still awake? Thank You!