Asthma in adult life - is there an association with birth weight?

Abstract

Objective - To determine whether birth weight is associated with asthmatic disorders in adult life. Design - A case-control study which compared birth weight and other indicators of pregnancy outcome in a group of adult asthmatic patients and in matched healthy controls. The diagnosis of asthma was verified using defined criteria. All asthmatic subjects were excluded from the control group. Setting - Four primary health care centres in Lund, Sweden. Subjects - 55 asthma patients and 92 healthy controls, all born between 1948 and 1973 in Lund. Main outcome measures - Birth weight, birth height, head circumference, placental weight, and gestational age. Data from a self-administered questionnaire on social and medical background factors including smoking, educational level, and a self-reported history of frequent severe respiratory infections in childhood. Results - No significant differences were found between asthma patients and controls in birth weight, 3529 (SD 533) g versus 3536 (501) g, or in other variables associated with pregnancy outcome. There were no differences in current smoking habits or in educational level between the groups. The asthma patients, however, reported a higher number of childhood respiratory infections (p<0.001) than the controls. Conclusions - These epidemiological findings do not lend support to the hypothesis that a reduced birth weight is associated with a ?programming? factor for asthma. Environmental factors in childhood seem more important than fetal malnutrition for the development of asthma in adult life.