First-year infections after initial hospitalization in low birth weight infants with and without bronchopulmonary dysplasia.

Symptoms of infection, specific infections, antibiotic course and hospitalizations were evaluated prospectively by using monthly questionnaires after initial hospitalization in 73 low birth weight (LBW) infants (less than 1751 g) and a subgroup of 19 infants with bronchopulmonary dysplasia (BPD) compared with 63 full-term controls matched for age, sex and home locality. The immunoglobulin G, A, M and E levels of the LBW infants were measured at corrected ages of 1, 2, 4, 6, 8, 10 and 12 months. The LBW infants, the subgroup with BPD and their controls had similar frequencies of infectious symptoms and episodes of infection. Dyspnoea and lower respiratory tract infections often caused by respiratory syncytial virus (RBV) were more frequent and more severe among LBW and especially BPD infants compared with controls. Male sex, a large family and day-care were significant risk factors for illness. The IgG levels of the LBW infants were subnormal at the corrected age of 1 month, but otherwise immunoglobulin levels were normal. The results suggest that LBW infants and especially those with BPD are prone to lower respiratory tract infections and should be considered candidates for immunoprophylaxis against RBV. In order to reduce morbidity home care is preferable to day-care.