Premature Labour -
Introduction
|
BMJ. 1999 Oct
23;319(7217):1093-7.
Prediction of survival for preterm births by weight and gestational age:
retrospective population based study.
Draper ES, Manktelow B, Field DJ, James D.
Department of Epidemiology, Leicester University Medical School,
Leicester LE1 6TP. msn@le. Ac.uk
Objectives:
To produce current data on survival of preterm infants.
Design:
Retrospective population based study.
Setting:
Trent health
region. SUBJECTS: All European and Asian live births, stillbirths, and
late fetal losses from 22 to 32 weeks' gestation, excluding those with
major congenital malformations, in women resident in the Trent health
region between 1 January 1994 and 31 December 1997. MAIN OUTCOME
MEASURES: Birth weight and gestational age specific survival for both
European and Asian infants (a) known to be alive at the onset of labour,
and (b) admitted for neonatal care.
Results:
738 deaths occurred in 3760
infants born between 22 and 32 weeks' gestation during the study period,
giving an overall survival rate of 80.4%. The survival rate for the 3489
(92.8%) infants admitted for neonatal care was 86.6%. For European
infants known to be alive at the onset of labour, significant variations
in gestation specific survival by birth weight emerged from 24 weeks'
gestation: survival ranged from 9% (95% confidence interval 7% to 13%)
for infants of birth weight 250-499 g to 21% (16% to 28%) for those of
1000-1249 g. At 27 weeks' gestation, survival ranged from 55% (49% to
61%) for infants of birth weight 500-749 g (below the 10th centile) to
80% (76% to 85%) for those of 1250-1499 g. Infants who were large for
dates (>/=27 weeks' gestation) had a slightly reduced, but not
significant, predicted survival. Similar survival rates were observed
for Asian infants. The odds ratio for the survival of infants from a
multiple birth compared with singleton infants was 1.4 (1.1 to 1.8).
Survival graphs for infants admitted for neonatal care are presented by
sex.
Conclusion:
Easy to use birth weight and gestational age specific
predicted survival graphs for preterm infants facilitate decision making
for clinicians and parents. It is important that these graphs are
representative, are produced for a geographically defined population,
and are not biased towards the outcomes of particular centres. Such
graphs, produced in two stages, allow for the changing pattern of
survival of infants from the start of the intrapartum period to
immediately after admission for neonatal care.
