Long-term outcomes of Prematurity

Gehan Roberts

Centre for Community Child Health, RCHMurdoch Childrens Research Institute

Department of Paediatrics, University of Melbourne

Contents

• Introduction– Definition– Prevalence

• History• Outcome studies– Changes over time

• Intervention studies• Future directions

Definition

Term: >=37• Preterm <37/40– Late preterm: 33 to 36+6– Very preterm: 28 to 32+6– Extremely preterm: <28• Alternative classifications based on birthweight– LBW <2500g– VLBW <1500g– ELBW <1000g

Prevalence

• Late preterm ~7% • Very preterm ~1-2%

• Victoria: 60-75,000 births p. year– About 5000 preterm– About 750 very preterm

History

• Victorian Infant Collaborative Study– ELBW infants (500-999g)– + <28/40 after 1991

• 5 cohorts– 1979-80, 1985-87, 1991-92, 1997, 2005

ELBW infants in Victoria

1979-80 n=351 (3.03/1000 livebirths) 175/yr

1985-87 n=560 (3.06/1000 livebirths) 187/yr

1991-92 n=429 (3.29/1000 livebirths) 215/yr1997 n=233 (3.77/1000 livebirths)

233/yr2005 n=257 (3.88/1000 livebirths)

257/yr

Traditional Outcomes

• Survival– Discharge– 2 years

• Neurological disability– Deafness– Blindness– Cerebral Palsy

Survival

0

20

40

60

80

100

79-80 85-87 91-92 1997 2005

500-999

% survival

Era

Survival

0

20

40

60

80

100

79-80 85-87 91-92 1997 2005

500-749

750-999

% survival

Era

Cerebral Palsy

0

5

10

15

20

79-80 85-87 91-92 1997 2005

% CP

Era

Blindness

0

2

4

6

8

10

79-80 85-87 91-92 1997 2005

% blind

Era

Deafness

0

2

4

6

8

10

79-80 85-87 91-92 1997 2005

% deaf

Era

Developmental outcomes

• Increasingly important– More very tiny babies surviving to school-age and

adulthood

• Need to compare outcomes against a control group– How are they doing compared with same-age

peers?

Cognitive Delay: age 2

0%

20%

40%

60%

80%

100%

79-80 85-87 91-92 1997 2005

nil mild moderate severe

% survivors

Era

What about older children?

• Cognitive skills– IQ– Language– Attention, Executive function

• Educational outcomes• Behavioural and Psychological outcomes– Autism, ADHD, mood problems

School readiness • ‘School readiness’

– Term 1st used a century ago– Assessment framework for understanding profiles

of strengths and vulnerabilities of the preschool-age child

• Very preterm children are at high risk of difficulties in school– 50% have academic/ behavioural difficulties

• Understanding readiness to learn– potential to aid successful transition into school

Definition• Three key attributes

– Children who are ready to learn– Schools that are ready for children– Parents and communities who support the child’s

development. • Readiness to learn is further divided into 5 skill areas

– 1) Health and physical development– 2) Emotional well-being and social competence– 3) Approaches to learning– 4) Communication skills– 5) Cognitive skills and general knowledge.

– Copple, National Educational Goals Panel, 1997

Cumulative number of areas of difficulty

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6

Number of Domains

Pro

po

rtio

n

VPT

Control

0 1 2 3 4 5

Meta-Analysis of Neurobehavioral Outcomes in Very Preterm Children.

Relationship between gestation and IQ

‘Preterm and low birth weight babies’, Dieter Wolke,Sage Handbook of Developmental Disorders

Relationship between gestation and IQ

‘Preterm and low birth weight babies’, Dieter Wolke,Sage Handbook of Developmental Disorders

‘Preterm behavioural phenotype’: increased inattention, anxiety, social difficulties

-Johnson et al, Ped Res, 2011

Prevalence of psychiatric disorders at 11 y of age in a population-based cohort 219 EPT (26 wk) children (BLUE)152 term-born classmates (RED) -UK EPICure Study

Swedish national cohort of 1 180 616children born between 1987 and 2000, followed up for ADHD medicationin 2006 at the age of 6 to 19 years

•Compared with term controls, VLBW adults (age 21 y) are…•More conscientious•Agreeable•Less open to new experiences•Less hostile or impulsive•Less assertive

•Independent of age, gender, school achievement, parental education, maternal health

•Pesonen et. al, Helsinki Study of VLBW adults, J Ch Psychol. Pstychiatr. 2008

•Compared with term controls, VLBW adults (age 21 y) are…•More conscientious•Agreeable•Less open to new experiences•Less hostile or impulsive•Less assertive

•Independent of age, gender, school achievement, parental education, maternal health

•Pesonen et. al, Helsinki Study of VLBW adults, J Ch Psychol. Pstychiatr. 2008

Preterm personality profilePreterm personality profile

Meta-analysis of logistic regressions of leisure timephysical activity as a function of birth weight. The points depictlog(OR) and corresponding 95% confidence intervals

Birth Weight in Relation to Leisure Time Physical Activityin Adolescence and Adulthood: Meta-Analysis of Resultsfrom 13 Nordic Cohorts. Andersen et al. PLoS ONE, 2009

Respiratory health

Preterm children, compared with term controls, have…•More hospital readmissions with URI/ LRIs•More airway obstruction•Poorer exercise tolerance

……in childhood, adolescence and early adulthood.

•This has not been affected by the introduction of Surfactant•Smoking probably contributes to worsening of these outcomes•Those who had BPD as neonates do worse than those who did not.

Quality of life

•Young adults born preterm:•report no differences in the self-reported quality of life despite recognition of their disabilities•‘the disability paradox’

•ELBW and control adolescents and their parents provide higher ratings of health-related quality of life for severely disabling hypothetical health states than did health professionals.

•Saigal, Lancet, 2008

Future directions

• Intervention– Long-term follow-up of promising NICU

interventions• Caffeine, DHA, antenatal Magnesium

– Interventions targeted to areas of vulnerability• Working memory• Social-emotional development

– Novel intervention delivery• Web-based?

25 weeks 26 weeks 30 weeks

32 weeks 34 weeks 40 weeks