Human Development

Late Preterm Delivery is STILL Premature — It's Worth the Weight to Wait!!

"Late Preterm" is Premature — It's Worth the Weight to Wait!!

Give Your Baby the Best Chance for a Healthy Start
39 Week Initiative of Birth Outcomes Project


 

Fetal Brain Development and Growth
— Lower functions mature first; the cerebral cortex is last to develop
— The brain at 35 weeks weighs only 2/3 what it will weigh at term
— The immature control of the late preterm brain can be evidenced by problems with periodic breathing, apnea, decreased HR variability, REM sleep difficulties, and feeding difficulties
— Volume of the cerebellum at 34 weeks is only 55% of that at term
— Cerebellar function is related to: fine motor control, coordination, motor sequencing, cognition and language, social function, and learning
— Volume of the white matter increases 5-fold from 35-41 weeks
— Cerebral cortex volume at 34 weeks is only 53% of the term volume
— Cerebral cortex is the seat of higher order functions: cognition, perception, reason, motor control
— The brain organizes during the late preterm period; there is tremendous development of synapses, axon growth, dendrites, and neurotransmitters in these final weeks
        

"Late Preterm" is Premature — It's Worth the Weight to Wait!!


There is an association between Gestational Age at Delivery and Special Education Need — the earlier the delivery, the higher the need for Special Education … the later the delivery, the lower the need for Special Education [retrospective cohort study of 407,503 schoolchildren, 2010, United Kingdom]

Morbidity (incidence of disease or rate of complications/adverse effects following a procedure):
In Massachusetts, a 2008 study found that 22% of Late Preterm Infants suffered morbidity, versus only 3% of Term Infants…
Morbidity rates doubled for each gestational week earlier than 38 weeks:
40 wks: 2.5%
39 wks: 2.6%
38 wks: 3.3%
37 wks: 5.9%
36 wks: 12.1%
35 wks: 25.6%
34 wks: 51.9%
[Shapiro-Mendoza et al, Effect of later-preterm birth and maternal medical conditions on newborn morbidity risk, Pediatrics, 2008. 121, 223-232]

What We Know:
— Widespread, convincing evidence that elective delivery under 39 weeks has increased morbidity
— There are still elements of fetal maturity occurring during the 38th to 39th week
—  Inducing women with an unfavorable cervix is associated with a higher cesarean rate
— There are significant challenges associated with implementing a "39 week" elective delivery policy
— The challenges can be overcome with appropriate leadership, oversight, and available tools
— In 2008, the rate of Late-Preterm Births (34-36 weeks) for All States was 12.3%

 

Why are Late Preterm Delivery Rates Rising?
— Changing culture of childbearing
— More high risk pregnancies
   * advanced maternal age, advanced paternal age
   * more complications such as infections, high blood pressure, gestational diabetes, obesity
   * more multiple births
   * high risk behaviors including substance abuse (smoking, drinking, illicit drug use)
— Public preferences / autonomy
   * date of delivery scheduled for convenience
   * cesarean delivery on maternal request (CDMR)

 

"Late Preterm" is Still Premature

 

— Late preterm infants (34-36 weeks) typically receive routine care in well-baby nurseries and are presumed low risk
— Problems may not be noticed until illness is more advanced and symptoms are evident
— Late preterm infants are much more likely than term infants to have:
   * NICU Admissions
   * depression at birth (low Apgar scores)
   * respiratory distress, including respiratory failure
   * hypoglycemia
   * feeding problems
   * temperature instability
   * apnea
[NICHD Invitational Conference, July 2005]

 

ACOG Evidence-Based Guidelines
NO elective induction or elective cesarean delivery before 39 weeks unless evidence of fetal lung maturity
To assess fetal lung maturity an amniocentesis is usually done to collect amniotic fluid for testing — as for any invasive procedure, there are potential risks

 

In Alabama, Southeastern Medical Center (SAMC) began the 39 Week Initiative in May 2011.
New Scheduling Policy for Cesarean Section and Induction of Labor
Documentation Criteria
Hard Stop on Under 39 Week deliveries without medical indications
New guidelines implemented on the standardization and management of oxytocin during labor.

A review of the First Quarter, May-July 2011:
Total Deliveries – 379
— 1 under 39 weeks delivery without medical indications
— neonatal morbidity due to under 39 week elective delivery (respiratory distress, temperature drops, feeding issues, jaundice) — 0.3% while prior data revealed a 63% morbidity
— overall SCN admission rates have declined by 33%
— neonatal transfer rates have declined by 66.7%

State-Wide Initiatives
Tennessee, Louisiana, North Carolina, California, Washington State, West Virginia, Florida