Maternal Prenatal Lifestyle Factors and Infectious Disease in Early Childhood: A Follow-Up Study of Hospitalization Within a Danish Birth Cohort

Abstract

Objectives. To examine whether maternal prenatal lifestyle factors were associated with the risk of hospitalization with infectious disease during early childhood and whether a possible association was modified by fetal growth reduction. Methods. The study was based on a birth cohort of 10 400 newborns whose mothers attended the midwife centers in Odense and Aalborg, Denmark, from April 1984 to April 1987 at approximately the 36th week of gestation. Information on hospitalization with infectious disease was extracted from the National Hospital Discharge Registry, and newborns were followed up to the end of 1996. Results. Among 6022 children who were hospitalized at least once, 31.4% (n = 1892) were hospitalized with infectious diseases. The cumulative incidence rate of hospitalization with infections in children from the age of 6 months to 12 years was 18.9%. The incidence rate ratio in children born to mothers smoking during pregnancy was 1.24 (95% confidence interval: 1.13–1.36) compared with those of nonsmoking mothers. Mothers whose body mass index was <18 kg/m2 were more likely to give birth to infants who were hospitalized with infectious disease (incidence rate ratio: 1.29; 95% confidence interval: 1.05–1.59). The increased risk was present in children only up to the age of 5 years. Conclusions. The study shows that maternal smoking during pregnancy and a low prepregnancy body mass index are associated with a higher risk of hospitalization with infectious disease during early childhood. These associations are independent of fetal growth indicators.