Transcript Mark - Associates In Newborn Medicine

2011 Strong Foundations Conference
Development of the Premature Infant:
Through the Lens of the Pediatrician and
Neonatologist
Mark Bergeron, MD, MPH
Associate Director, Neonatal Medicine and
Neonatal Developmental Follow-up Clinic
Children’s Hospitals and Clinics of
Minnesota – St. Paul
Assistant Professor, Pediatrics
University of Minnesota Medical School
Objectives
• Discuss prematurity as
public health issue
– Review morbidity and
mortality data
• Highlight infant health
issues resulting from
prematurity
• Understand the impact
of prematurity on
infant/child
development
– Brain injury and
impairment
• Provide an overview
of short- and longterm measures to
address developmental
issues
What is Preterm?
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Term: ≥ 37 weeks postmenstrual age
Late Preterm: 34-36 weeks
Moderately Preterm: 32-33 weeks
Very Preterm: 28-31 weeks
Extremely Preterm < 28 weeks
Preterm Birth Statistics
Data: PeriStats, March of Dimes
Photo: Children’s Hospitals and Clinics of Minnesota
Cost of Preterm Birth
.
Data: PeriStats, March of Dimes
Photo: Children’s Hospitals and
Clinics of Minnesota
The First Hurdle: Survival
• Survival is inversely proportional to
gestational age:
– “Later is better!”
Data: Children’s Hospitals
and Clinics of Minnesota
Survival by Gestational Age
The Second Hurdle: “Meaningful” Survival
Data: Children’s Hospitals and
Clinics of Minnesota
Health Problems Associated with
Prematurity
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Heart and circulation
Lung function
Breathing
Feeding and Digestion
Lack of weight gain
Brain hemorrhages
Immature immune system
Informed Consent to Treat:
“NICU Alphabet Soup”
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PDA- Patent Ductus Arteriosis (heart)
NEC- Necrotizing Enterocolitis (digestive)
ROP- Retinopathy of Prematurity (eyes)
RDS- Respiratory Distress Syndrome
(lungs)
• CLD- Chronic Lung Disease (lungs)
• PVL- Periventricular Leukomalacia (brain)
• IVH- Intraventricular Hemorrhage (brain)
Intraventricular Hemorrhage (IVH): A
Marker for Developmental Problems
Data: Children’s Hospitals and Clinics of Minnesota
The Impact of Prematurity
• Serious implications for parents, health care
team:
– Survival is NOT a given
– Risk of poor developmental outcome must be
weighed carefully when making medical
decisions
• Fundamental Question: What does
prematurity mean for the baby’s
developmental potential?
Variables that affect the premature
infant’s developmental trajectory:
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Gestational age
Birth weight
Incidence/severity of lung disease
Time spent on mechanical ventilation
Need for oxygen
White matter brain injury (IVH, PVL)
Overall length of time in the NICU
Weight gain
Neurodevelopmental Issues in the Preterm
Infant
Brain growth in fetal life and
infancy
• During specific times in gestation, different types of cells
increase and mature structurally
• Almost all neurons are present by 18-20 weeks gestation
(good and bad news)
• The cells that perform basic thinking and control functions
of the brain are in place
• The total number of neurons increase only slightly, glial
cells increase until 2 years of age
• Myelination continues until 4 years of age (longer?)
• Synaptic rearrangements occur for years
Brain growth in the last trimester
• Growth of the cerebellum: muscles and
coordination of movement
• Pattern of dendritic connections between neurons
– Cerebellum is one of the most vulnerable areas for
preemies because it has a spurt of growth at 30-32
weeks gestation and is complete by 12 months of age
– When born prematurely, the dendritic connections are
developing under different circumstances where
nutrition and metabolic are key
Brain Injury in infancy
• Fetuses and neonates are uniquely
vulnerable to brain injury
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Decreased oxygen supply
Increased oxygen supply
Decreased blood flow
Bleeding
Infection
Toxins
Radiologic(?)
Brain Injury: Intraventricular
Hemorrhage (IVH)
• ssf
pediatriceducation.org
Brain Injury: Periventricular
Leukomalacia (PVL)
radiologyassistant.nl
Preterm Brain Injury: Long Term Effects
• Motor
• Cognitive
– Hypotonia (initially)
– Hypertonia
• Cerebral palsy
– Spastic diplegia
– Delays
• Gross
• Fine
– Delays
– MR
• Speech/Language
– Delays
• Expressive
• Receptive
Physiological Regulation and Development
• Preterm birth is a tremendous physiological stress
– Uterus vs. NICU incubator
• The preterm infant is developmentally unprepared for
the change from the intrauterine environment
– Sights
– Smells
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Sounds
_ Pain
• Response to stimulation is altered
– Preemies have instability of respiratory, heart rates and
temperature which become learned responses to stimulation
Mitigating Factors - NICU
• Family-centered care
– Encourage family
presence and
involvement
• Kangaroo care
• Developmentallyappropriate
environment
– Sound
– Light
– Temperature
Family-centered NICU Care
• Video: "NICU: the Garden of Hope"
Long-term Follow-up: A
Multidisciplinary Approach
• Primary care provider
– Well baby care
• Routine developmental
assessments
• Home health nursing
• Local programming
– Early Intervention
• Specialty care
– i.e. pulmonology
• NICU Follow-up
Clinic
– Scheduled
developmental
assessment
• Bayley Scales of Infant
• Rossetti Infant –
Toddler Language Scale
• Wechsler Preschool and
Primary Scale of
Intelligence - Revised
NICU Follow-up Clinic Referral Criteria
Children’s – St. Paul
• Birthweight ≤ 1500g
• ≤ 30 weeks GA
• > 48 hrs mechanical
ventilation
• Seizures
• Neurologic
abnormality
• Grade 3-4 IVH
• BPD
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IUGR
Congenital infection
Exchange transfusion
Therapeutic
hypothermia for HIE
• Other
– Neonatologists’
discretion
NICU Follow-up Clinic Team
• Pediatric Nurse
Practitioner
• Occupational
Therapist
• Developmental
Psychologist
• Speech/Language
Pathologist
• Neonatologist
Developmental Expectations
• Chronologic vs. “Adjusted” age?
– Developmental milestones and growth parameters
should be benchmarked against norms corrected
for prematurity.
• i.e. subtract the “weeks or months born early” from
chronological age.
– Example: Now 6 m.o. infant born at 32 weeks (2 months
preterm):
6 months. – 2 months = 4 months corrected age
Developmental Expectations, continued
• Conventionally, adjusted age is utilized until 24 months in
clinical settings
– Developmental testing
– NICU Follow-up clinic
• Practically, adjusted age remains useful
– Early Intervention (many preemies eligible until age 3)
– Decisions regarding preschool and kindergarten
readiness
• Physical
• Cognitive
• Emotional
Learning Behaviors-Special Considerations
• When development is measured early on, former preemies
may not do as well due to greater difficulty focusing
attention on task completion
– Altered learning patterns?
• Altered response to stress/stimulation
• May need more repetitive play to learn skills
• Special risks
– ADHD
– Autism spectrum disorders (controversial)
Summary
• Preterm birth remains an important public
health issue
• As extreme preterm birth-related mortality
has decreased, morbidity, especially
neurologic, has increased
• Much has been done to support premature
infants’ developmental needs, both in the
short- and long-term
Resources
• American Academy of Pediatrics
– www.aap.org
• American Academy of Pediatrics Section on Perinatal Pediatrics
– www.aap.org/sections/perinatal/index.html
• March of Dimes
– www.modimes.org
• Children’s Hospitals and Clinics of Minnesota Neonatal Cornerstone
Program
– www.childrensmn.org/Services/Neonatal/
• Associates in Newborn Medicine, P.A.
– www.newbornmed.com
• Minnesota Perinatal Organization and Minnesota Prematurity
Coalition
– www.minnesotaperinatal.org
Questions/Comments
• Mark Bergeron:
– [email protected]