Development of the Premature Infant: Through the Lens of the Pediatrician and Neonatologist

1. 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

2. 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 long-term measures to address developmental issues

3. What is Preterm? • Term: ≥ 37 weeks postmenstrual age • Late Preterm: 34-36 weeks • Moderately Preterm: 32-33 weeks • Very Preterm: 28-31 weeks • Extremely Preterm < 28 weeks

4. Preterm Birth Statistics Data: PeriStats, March of Dimes Photo: Children’s Hospitals and Clinics of Minnesota

5. Cost of Preterm Birth . Data: PeriStats, March of Dimes Photo: Children’s Hospitals and Clinics of Minnesota

6. The First Hurdle: Survival • Survival is inversely proportional to gestational age: • “Later is better!” Data: Children’s Hospitals and Clinics of Minnesota

7. Survival by Gestational Age

8. The Second Hurdle: “Meaningful” Survival Data: Children’s Hospitals and Clinics of Minnesota

9. Health Problems Associated with Prematurity • Heart and circulation • Lung function • Breathing • Feeding and Digestion • Lack of weight gain • Brain hemorrhages • Immature immune system

10. Informed Consent to Treat: “NICU Alphabet Soup” • 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)

11. Intraventricular Hemorrhage (IVH): A Marker for Developmental Problems Data: Children’s Hospitals and Clinics of Minnesota

12. 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?

13. Variables that affect the premature infant’s developmental trajectory: • 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

14. Neurodevelopmental Issues in the Preterm Infant

15. 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

16. 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

17. Brain Injury in infancy • Fetuses and neonates are uniquely vulnerable to brain injury • Decreased oxygen supply • Increased oxygen supply • Decreased blood flow • Bleeding • Infection • Toxins • Radiologic(?)

18. Brain Injury: Intraventricular Hemorrhage (IVH) • ssf pediatriceducation.org

19. Brain Injury: Periventricular Leukomalacia (PVL) radiologyassistant.nl

20. Preterm Brain Injury: Long Term Effects • Motor • Hypotonia (initially) • Hypertonia • Cerebral palsy • Spastic diplegia • Delays • Gross • Fine • Cognitive • Delays • MR • Speech/Language • Delays • Expressive • Receptive

21. 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 _ Sounds • Smells _ Pain • Response to stimulation is altered • Preemies have instability of respiratory, heart rates and temperature which become learned responses to stimulation

22. Mitigating Factors - NICU • Family-centered care • Encourage family presence and involvement • Kangaroo care • Developmentally-appropriate environment • Sound • Light • Temperature

23. Family-centered NICU Care • Video: "NICU: the Garden of Hope"

24. 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

25. NICU Follow-up Clinic Referral CriteriaChildren’s – St. Paul • Birthweight ≤ 1500g • ≤ 30 weeks GA • > 48 hrs mechanical ventilation • Seizures • Neurologic abnormality • Grade 3-4 IVH • BPD • IUGR • Congenital infection • Exchange transfusion • Therapeutic hypothermia for HIE • Other • Neonatologists’ discretion

26. NICU Follow-up Clinic Team • Pediatric Nurse Practitioner • Occupational Therapist • Developmental Psychologist • Speech/Language Pathologist • Neonatologist

27. 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

28. 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

29. 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)

30. 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

31. 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

32. Questions/Comments • Mark Bergeron: • berge356@umn.edu