Delays in Receipt of Immunizations in Low-Birth-Weight Children

Background Studies of very low-birth-weight (VLBW) children discharged from neonatal intensive care units have shown delays in receipt of routine childhood immunizations. However, a recent study of VLBW children in 3 health maintenance organizations found no significant delays in immunizations. Objective To assess the risk of immunization delays for moderately low-birth-weight (MLBW; 1500 g-2499 g) and VLBW (<1500 g) children compared with normal-birth-weight children in a nationally representative birth sample. Design Logistic regression analysis using the 1988 National Maternal and Infant Health Survey and the 1991 Longitudinal Follow-up Survey. Setting Nationally representative sample of children born in 1988 in the United States. Participants A total of 8285 children whose mothers completed both surveys. Main Outcome Measures Age at receipt of each of the first 4 doses of diphtheria and tetanus toxoids and pertussis vaccine, the first 3 doses of polio vaccine, and the first dose of measles-mumps-rubella vaccine for MLBW and VLBW children, and normal-birth-weight children. We also examined whether children were up-to-date for all immunizations at ages 12, 24, and 36 months based on birth-weight groups. Results Very low-birth-weight children received their first 3 doses of diphtheria and tetanus toxoids and pertussis vaccine and their first 2 doses of polio vaccine significantly later than normal-birth-weight children (P<.001). Very low-birth-weight children were significantly less likely to be up to date for all immunizations at ages 12 months (odds ratio [OR] = .556;P= .001), 24 months (OR = .439;P<.001), and 36 months (OR = .446;P<.001) compared with normal-birth-weight children. Conclusion Very low-birth-weight children are at risk for immunization delays compared with normal-birth-weight children.