Background: Preterm birth and reduced intrauterine growth appear to be related to morbidity in childhood and later adulthood. We studied whether the risk of all-cause hospitalization in adolescence and early adulthood differed between individuals who were born preterm or small for gestational age (SGA) compared with those born at term and appropriate for gestational age.
Methods: Using Swedish registries, we followed 304,275 men and women born in 1973-1975 for any hospitalizations occurring in 1987-1996. Preterm birth was defined as <37 weeks of gestation and SGA as babies smaller than 2 standard deviations below the mean weight for gestational length, according to Swedish standards. We created 3 mutually exclusive categories: "preterm" (<37 weeks and not SGA), "SGA" (SGA and not preterm), and "both preterm and SGA." The comparison group was all term births not SGA. Childhood socioeconomic characteristics were accounted for in the analyses.
Results: The overall risk of hospitalization was higher for men and women born SGA (adjusted odds ratio = 1.16; 95% confidence interval = 1.12-1.21), for those born preterm (1.06; 1.02-1.10), and for those born both preterm and SGA (1.42; 1.26-1.59). In addition to higher risks for previously reported adverse health outcomes, such as neurodevelopment sequelae and congenital anomalies, men and women born SGA or preterm were more likely to be hospitalized due to unspecified symptoms. SGA also appeared to be associated with genitourinary diseases and drug use.
Conclusions: Men and women born SGA or preterm were at higher risk for hospitalization during adolescence and early adulthood, with men and women born SGA more at risk than those born preterm.