Long-Term Survival of Individuals Born Small and Large for Gestational Age

<div><p>Background</p><p>Little is known on long-term survival and causes of death among individuals born small or large for gestational age. This study investigates birth weight in relation to survival and causes of death over time.</p><p>Methods</p><p>A national cohort of 1.7 million live-born singletons in Denmark was followed during 1979–2011, using the Danish Civil Registration System, the Medical Birth Registry and the Cause of Death Registry. Cox proportional hazards were estimated for the impact of small (SGA) and large (LGA) gestation weight and mortality overall, by age group and birth cohort.</p><p>Results</p><p>Compared to normal weight children, SGA children were associated with increased risk of dying over time. Though most of the deaths occurred during the first year of life, the cumulative mortality risk was increased until 30 years of age. The hazard ratios [HR] for dying among SGA children ages <2 years were: 3.47 (95% CI, 3.30–3.64) and 1.06 (95% CI, 0.60–1.87) in 30 years and older. HR for dying among SGA adults (20–29 years) were: 1.20 (95% CI, 0.99–1.46) in years 1979–1982 and 1.61 (95% CI, 1.04–2.51) in years 1989–1994. The SGA born had increased risk of dying from infection, heart disease, respiratory disease, digestive disease, congenital malformation, perinatal conditions, and accidents, suicide, and homicide. Individuals born LGA were associated with decreased mortality risk, but with increased risk of dying from malignant neoplasm.</p><p>Conclusions</p><p>Survival has improved independently of birth weight the past 30 years. However, children born SGA remain at significantly increased risk of dying up till they turn 30 years of age. Individuals born LGA have lower mortality risk but only in the first two years of life.</p></div

Infant Baseline Characteristics 1979–2011.

<p>*grams</p><p>**weeks</p><p>Infant Baseline Characteristics 1979–2011.</p

Mortality and Relative Birth Weight by Age Group 1979–2011.

<p>Abbreviation: SGA, small for gestational age; LGA, large for gestational age; HR, Hazard ratio; CI, Confidence interval</p><p>Mortality and Relative Birth Weight by Age Group 1979–2011.</p

Overall mortality risk by relative birth weight, time period 1979–2011.

<p>Hazard ratio and 95% confidence interval presented with 50^th percentile as the reference group.</p

Mortality by Relative Gestational Weight and Cause of Death 1979–2011.

<p>Abbreviation: SGA, small for gestational age; LGA, large for gestational age; HR, Hazard ratio; CI, Confidence interval</p><p>*Person-Years of Follow-Up (1000s): SGA, 7546; Normal, 29137; LGA, 2929</p><p>Mortality by Relative Gestational Weight and Cause of Death 1979–2011.</p

Mortality and Relative Birth Weight by Age and Birth Cohort Among Individuals Born Between 1979 and 2011.

<p>Abbreviation: SGA, small for gestational age; LGA, large for gestational age; HR, Hazard ratio; CI, Confidence interval; NA, not applicable</p><p>Mortality and Relative Birth Weight by Age and Birth Cohort Among Individuals Born Between 1979 and 2011.</p