A new study by March of Dimes reports that
preterm birth and birth defects are associated with each other.
"Babies born preterm were more than twice as likely to have
major birth defects as full-term infants, according to a new
analysis of nearly 7 million U.S. live births published online
this week in the Springer journal Maternal and Child Health
Journal."
A similar conclusion has been reached by the study published in
the March 12 issue of JAMA and titled Association of Preterm
Birth With Long-term Survival, Reproduction, and Next-Generation
Preterm Birth.
Preterm birth is a major cause of infant morbidity and
mortality. Less is known about long-term health among persons
born preterm.
Objective To determine the long-term effects of preterm birth on
survival, reproduction, and next-generation preterm birth.
Design, Setting, and Participants Population-based,
observational, longitudinal study using registry data from 1 167
506 singleton births in the Medical Birth Registry of Norway in
1967-1988. The cohort was followed up through 2002 for survival.
The cohort was truncated to births from 1967-1976 for assessment
of educational achievement and reproductive outcomes through
2004.
Main Outcome Measures In relation to sex and gestational age at birth,
absolute mortality, risk of fetal, infant, child, and adolescent mortality,
and incidence and risk of reproduction and next-generation preterm birth.
Singleton term (37-42 weeks) fetal deaths and live births, stratified by
sex, served as the reference group for all analyses.
Results The percentage who were born preterm was higher among boys (5.6%)
than among girls (4.7%). Preterm participants had an increased risk of
mortality throughout childhood. For boys born at 22 to 27 weeks, mortality
rates were 1.33% and 1.01% for early and late childhood death, with relative
risks (RRs) of 5.3 (95% confidence interval [CI], 2.0-14.2) and 7.0 (95% CI,
2.3-22.0), respectively. The mortality rate for girls born at 22 to 27 weeks
was 1.71% for early childhood death, with an RR of 9.7 (95% CI, 4.0-23.7);
there were no late childhood deaths. For 28 to 32 weeks, the early and late
childhood mortality rates among boys were 0.73% and 0.37%, with RRs of 2.5
(95% CI, 1.6-3.7) and 2.3 (95% CI, 1.3-4.1), respectively. Girls born at 28
to 32 weeks did not have a significantly increased risk of childhood
mortality. Reproduction was diminished for index participants born preterm.
For men and women born at 22 to 27 weeks, absolute reproduction was 13.9%
and 25%, with RRs of 0.24 (95% CI, 0.17-0.32) and 0.33 (95% CI, 0.26-0.42),
respectively. For 28 to 32 weeks, absolute reproduction was 38.6% and 59.2%
for men and women, with RRs of 0.7 (95% CI, 0.66-0.74) and 0.81 (95% CI,
0.78-0.85), respectively. Preterm women but not men were at increased risk
of having preterm offspring.
In persons born in Norway in 1967-1988, preterm birth was associated with
diminished long-term survival and reproduction.
