| Abstract: | 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. 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. CONCLUSION: In persons born in Norway in 1967-1988, preterm birth was associated with diminished long-term survival and reproduction.
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