Importance of preterm birth

1
Importance of preterm birth

• Session 1 Chairman
• Professor Nicola Rizzo
• Clinica Osterrica e Ginecologica, Bologna, Italy

1st International Preterm Labour Congress,
Montreux, Switzerland, June 2002
2
Defining the problem of preterm birth review of
epidemiology

• Professor Judith Lumley
• Centre for the Study of Mothers and Childrens
  Health, Carlton, Australia

1st International Preterm Labour Congress,
Montreux, Switzerland, June 2002
3
Factors affecting registration 1

• National or regional criteria for the
  registration of a fetal death (ranging from 16
  weeks to 28 weeks)
• Under-registration of stillbirths and live births
  close to the registration boundary
• Under-registration of live births when a still
  birth at the same gestation would not require
  registration

Judith Lumley
4
Factors affecting registration 2

• The perception that some extremely small- or
  extremely preterm-live born infants are
  non-viable (increased registration with
  availability of intensive care)
• Exclusion of legal terminations of pregnancy from
  birth registration even when the duration of the
  pregnancy would require registration had a birth
  occurred

Judith Lumley
5
Recent changes in practice

• Early termination of pregnancy following prenatal
  diagnosis of a birth defect
• Fetal reduction of twin pregnancies to a single
  pregnancy prior to the registration boundary
• Exclusion of births from birth registration if
  the death of the fetus is believed to have
  occurred prior to the registration boundary even
  though the pregnancy continued past that point

Judith Lumley
6
Increases in preterm birth

• Improved ascertainment close to the registration
  boundary (?29 VIC)
• Increase in multiple births
• Twins ?40
• Triplets ?400 USA
• Increase in singletons from assisted conception
• Elective caesarean for maternal/fetal indication

Judith Lumley
7
Implications of changing social factors

• Reductions in social inequality, ? preterm birth
• A fall in the proportion of births to young
  women, ? preterm birth
• An increase in the proportion of births to older
  women, ? preterm birth
• A decrease in the proportion of women who are
  married, ? preterm birth

Judith Lumley
8
Ways forward

• Improvements in measurement of social and
  bio-behavioural factors
• Conceptual frameworks for causal paths between
  socio-economic factors and preterm birth
• Population-based cohort and case-control studies
  of preterm birth including measurements of
  biological markers, molecular epidemiology
• Multi-level modelling of risk factors

Judith Lumley
9
Classification and heterogeneity of preterm birth

• Professor Robert Ward
• University Medical Center, Salt Lake City, USA

1st International Preterm Labour Congress,
Montreux, Switzerland, June 2002
10
Increasing survival extremely low birthweight
1980 to 2000 University of Utah
Robert Ward
11
Major neonatal complications following preterm
birth

• ? RDS ? Nosocomial infections
• ? ROP ? Developmental delay
• ? IVH/PVL ? Reduced growth
• ? Chronic lung disease ? Patent ductus
  arteriosus
• ? Barotrauma ? Hearing impairment
• ? NEC ? perforation ? Neonatal abstinence
• ? Catheter complications
• Too many complications to discuss them all

Robert Ward
12
RDS, pneumothorax, discharge w/O2

Redrawn from data from 2001 Vermont Oxford
Network
Robert Ward
13
Intraventricular haemorrhage and cystic
periventricular leucomalacia
Redrawn from data from 2001 Vermont Oxford Network
Robert Ward
14
Necrotising enterocolitis and perforation
NEC
Perforation
9
8
7
6
5

4
3
2
1
0
501750 g
7511000 g
10011250 g
12511500 g
Redrawn from data from 2001 Vermont Oxford Network
Robert Ward
15
Necrotising enterocolitispathophysiology and
outcomes

• Ischaemic? mucosal damage, prematurity, formula
  feeds, bacteria produce H2 in bowel wall
• Bilious emesis, haematochezia, signs of sepsis,
  pneumatosis intestinalis/portal gas or bubbly gas
  pattern
• Surgery for perforation, dilated loop or
  coagulopathy vs peritoneal drains and antibiotics
• Outcomes mortality 1050, strictures 30, short
  bowel syndrome, hyperal-related cirrhosis

Robert Ward
16
Retinopathy of prematurityfrequency of stages by
birth weight
Redrawn from data from 2001 Vermont Oxford Network
Robert Ward
17
Neonatal complications following preterm birth

• Cause acute and long-term mortality and morbidity
• Increase, in general, with greater immaturity
• Anecdotally, complications seem to cluster in a
  few infants with severe RDS unimproved by
  surfactant who develop pulmonary barotrauma,
  sepsis, IVH, NEC, BPD and ROP
• ? Inherited susceptibility to complications,
  possibly through poor control of inflammation or
  inadequate capacity to heal

Robert Ward
18
Economic consequences of preterm birth

• Dr Stavros Petrou
• National Perinatal Epidemiology Unit, Oxford, UK

1st International Preterm Labour Congress,
Montreux, Switzerland, June 2002
19
Literature search strategy

• Literature sources
• computerised databases, British Theses, CRIB,
  hand searches, contacts with other researchers,
  bibliographies of economic evaluations
• Search terms prematurity preterm birth low
  birthweight
• Timeframe 19801999
• Excluded studies developing country research,
  non-English language

Stavros Petrou
20
Cost of neonatal care by birthweight
UK 1998 prices
Population
95 CI
No. of
Mean
studies
cost per
Low
High
case
lt 1000 g
21
39,483
30,466
48,500
10001500 g
15
22,541
14,780
30,302
gt 1500 g
4
9,207
4,295
14,119
Stavros Petrou
21
Other economic implications

• Additional educational assistance (Lewis et al
  1995)
• high rates of school failure
• increased risk of grade repetition
• Reduction in family income (Gennaro 1996)
• Intangible costs (Cronin et al 1995)
• emotional and physical energy
• isolation of mother
• restricted social contact
• increased risk of marital break-up

Stavros Petrou
22
Economic evaluations of neonatal intensive care
Neonatal group
Periods compared
Study
Cost ( 1998)
Additional cost per additional survivor
lt 1000 g
19649 19737
Boyle
et al
(1983)
174,070
1000-1499 g
1964-9 1973-7
Boyle
et al
(1983)
101,030
24-28 weeks
1971-4 1977-83
Doyle
et al
56,080
(1989)
24-28 weeks
1977-83 1984-86
Doyle
et al
(1989)
89,680
Additional cost per additional life-year gained
lt 1000 g
1964-9 1973-7
Boyle
et al
(1983)
15,790
1985-7 1991-2
Kitchen
et al
(1997)
2,250
(1983)
1000 1499 g
1964-9 1973-7
Boyle
et al
4,920
Additional cost per additional QALY gained
lt 1000 g
1964-9 1973-7
Boyle
et al
(1983)
38,030
1985-7 1991-2
Kitchen
et al
(1997)
2,990
1000 1499 g
1964-9 1973-7
Boyle
et al
5,430
(1983)
Stavros Petrou
23
Cost-effectiveness of prevention and treatment of
RDS
Group
Study
Additional cost
per additional
survivor (1998)
Surfactant treatment for RDS vs no treatment
25-29 weeks
Maniscalco
et al
(1989)
No difference
Preterm
Tubman
et al
(1990)
9,667
Prophylactic surfactant vs no surfactant
lt 35 weeks
Mugford
et al
(1991)
15,054
Antenatal
corticosteroids vs none
lt 35 weeks
Mugford
et al
(1991)
Net saving
lt 31 weeks
Egberts (1992)
Net saving
Stavros Petrou
24
Conclusions

• The costs of preterm birth are substantial and
  persist into mid-childhood
• In addition to the costs borne by health
  services, preterm birth imposes an economic
  burden on other sectors and on individuals
• Information on incremental costs and incremental
  benefits required for the purposes of allocative
  efficiency

Stavros Petrou
25
The impact of multiple preterm birth on the
family

• Dr Elizabeth Bryan
• Multiple Births Foundation, London, UK

1st International Preterm Labour Congress,
Montreux, Switzerland, June 2002
26
Twinning rates per 1000 births in ten countries
19751995
Y Imaizumi. Acta Genet Med Gemellol 199847101
Elizabeth Bryan
MBF
27
Perinatal factors
Birthweight distributions of
singleton and multiple births
Elizabeth Bryan
UK Triplet Study 1990
28
Cerebral palsy in twins

100
Cerebral palsy
90
Not cerebral palsy
80
70
60
50
Cumulative percentage
40
30
20
10
0
20
25
30
35
40
45
Gestational age (weeks)
Yokoyama et al. Int J Epidem 199524943
Elizabeth Bryan
MBF
29
Mortality in multiple births England and Wales
1998per 1,000 births
Elizabeth Bryan
30
Maternal behaviour toward premature twins

• Fewer initiatives and responses
• Less responsive to positive signals
• Less responsive to crying
• Lifted, held, touched, patted less
• Talked less
• Maternal behaviour was predictive of cognitive
  development at 18 months

Ostfeld et al. Twin Research 20003234-41
Elizabeth Bryan
31
Multifetal pregnancy reduction
The
choice
Continue
Reduce
Healthy babies
Pride
Miscarriage
More children
Survivor injury
Death
Guilt
Disability
Bereavement
Cost (e,p,f)
Elizabeth Bryan
Effect on survivors?