The premature newborn infant
Ola Didrik Saugstad
Department of Pediatric Research
Rikshospitalet University Hospital
University of Oslo, Norway
Student lecture 9th semester
Prematurity
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GA < 259 days (37 weeks)
Norway: 5.6% (1988) and 6.5% (1996)
< 1.5 kg 0.7-1.0% (528 = 0.9% in 1996)
< 1.0 kg 0.3 % (200 =0.3% in 1996)
USA: 7% among caucasians 18%
among black
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 < 28 weeks
Immature organ systems, intensive care
Slight and moderate approx 3000, severe 200 (0.3-0.4%) per year
Terminology
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Low birth weight < 2.5 kg
Very Low Birth Weight < 1.5 kg
Extremely Low birth Weight < 1.0 kg
Premature < 37 weeks
Immature < 28 weeks
ELGAN: Extremely Low Gestational Age
Newborn < 26 weeks
• Small for gestational age < 2.5 percentile
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
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
Survival
Gestational age weeks
21
22
23
24
25
26
NFR’s Consensus report 1999
Survival %
0-4
0-12
8-36
12-62
31-79
53-85
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
(O’Shea 1997)
Injury of ELGANs 1972-1990
< 26 uker < 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 > 4000 children)
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)
Development and pathogenesis of ROP
Impact of BPD, Brain Injury &
ROP on 18 m Outcome of ELBW
Infants
Overall probability of a
poor outcome @ 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 2003;289:1121-
School problems
• A Dutch study showed that > 50% with BW < 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 )
Boys> girs
Low Socioeconomic conditions
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