The premature newborn infant

1
The premature newborn infant

• Ola Didrik Saugstad
• Department of Pediatric Research
• Rikshospitalet University Hospital
• University of Oslo, Norway
• Student lecture 9th semester

2
Prematurity

• GA lt 259 days (37 weeks)
• Norway 5.6 (1988) and 6.5 (1996)
• lt 1.5 kg 0.7-1.0 (528 0.9 in 1996)
• lt 1.0 kg 0.3 (200 0.3 in 1996)
• USA 7 among caucasians 18 among black

3
Preterm infants

• Slight 32-36 weeks
• Feeding and temperature problems, some have
  immature lungs
• Moderate 28-31 weeks
• Immature lungs, temperature control, feeding
  problems, apneas
• Severe lt 28 weeks
• Immature organ systems, intensive care

Slight and moderate approx 3000, severe 200
(0.3-0.4) per year
4
Terminology

• Low birth weight lt 2.5 kg
• Very Low Birth Weight lt 1.5 kg
• Extremely Low birth Weight lt 1.0 kg
• Premature lt 37 weeks
• Immature lt 28 weeks
• ELGAN Extremely Low Gestational Age Newborn lt 26
  weeks
• Small for gestational age lt 2.5 percentile

5
General problems in premature infants

• Feeding (IV Gavage)
• Temperature control (incubator-heated bed)
• Respiratory control apneas, Respiratory support
  CPAP, Artificial ventilation
• Immature lungs lack of surfactant Oxygen
  suppl, Respiratory support (CPAP, ventilator)
• Immature brain brain hemorrhage and cysts
• Immunology risk of infections (antibiotics)
• Organ injury (Brain, Eye, Lung, Intestine, Skin
• Long term consequences

6
Survival

• 1940 50 with BW1500 gram survive
• 2000 50 with BW 600 gram survive
• Birth weight Survival after 1 year
• 350-499 g 14
• 500-799 g 47
• 750-999 g 76_______________
• Medical Birth Registry 1992-96

7
Survival

• Gestational age weeks Survival
• 21
  0-4
• 22
  0-12
• 23
  8-36
• 24
  12-62
• 25
  31-79
• 26
  53-85
• NFRs Consensus report 1999

8
Sequels

• From 1979 to 1994 survival among preterm
  infatns with BW 501-800 gr increased from 20 to
  59.
• The percentage of children with severe
  neurosensory injury was however, unchanged
• (OShea 1997)

9
Injury of ELGANs 1972-1990

• lt 26 uker lt
  800 gram
• Mental retardation 14 14
• Cerebral palsy 12
  8
• Blindness 8
  8
• Deafness 3
  3
• Major disability 22
  24
• Survival increased, however rate of injury was
  constant

Lorents JM et al 1998, (meta-analysis including gt
4000 children)
10
Injury of preterm infants

• Eye ( Retinopathy of prematurity ROP
• Stage 1-5)
• Brain injury (Intracranial hemorrhage (grade 1-4)
  Periventricular leukomalacia PVL). Immature
  capillaries (plexus Choroides), hemodynamic
  changes, intrauterine inflammation
• Pulmonary ( Bronchopulmonary dysplasia - BPD,
  Chronic lung disease - CLD)
• Intestinal (necrotizing enterecolitis - NEC)

11
Development and pathogenesis of ROP
12
Impact of BPD, Brain Injury ROP on 18 m Outcome
of ELBW Infants
Overall probability of a poor outcome _at_ 18 m (35)
A simple count of 3 common neonatal morbidities
strongly predicts the risk of later death or
disability
Schmidt B et al. JAMA. March 20032891121-29
13
School problems

• A Dutch study showed that gt 50 with BW lt 1500
  gram needed extra support at school
• No relation between Gestational age and injury
• Preterm infants have to be followed-up at least
  till school age because these problems have a
  late debut. Learning problems picked up around 8
  years
• ADHD
• Hyperactivity
• Intellectual problems (arithmetics, solving
  problems, cognitive functions)
• Short term memory
• Coordination problems
• Behavioral problems (shy, sport performance,
  sosialise )
• Boysgt girs
• Low Socioeconomic conditions

14
Future challenges

• Prevent preterm birth
• Understand relation between intrauterine
  conditions and postnatal injury
• Improved nutrition
• Improved technology
• New drugs (antioxidants, anti inflammatory, etc)
• New insight into the needs and the psychological
  development