Background: The proportion of infants in the United States adequately immunized with DTP (Diphtheria, Tetanus and Pertussis) vaccine is below other industrialized nations and lowest among infants living in urban areas. At present, predictors of poor immunization are not well developed. In particular, the relationship between prenatal care utilization and childhood vaccination is not clearly defined.
Methods: Using medical record data, we measured associations between prenatal variables and adequacy of immunization (three DTP vaccines by age 10 months) in 163 mother-infant pairs who received prenatal and child care at a neighborhood community health center.
Results: At the end of 10 months' follow-up, 29.4% of infants had not received three DTP immunizations. Logistic regression identified the following independent risk factors for immunization delay: multiparity, being an English-speaking Hispanic mother, and failing to attend scheduled prenatal care appointments. In the regression model, interactions also existed between having a high proportion of missed visits to total prenatal visits scheduled (> or = 25%) and receiving social services, with the highest risk existing for women with a high proportion of missed appointments who also received social services, and the lowest for those with < 25% missed appointments who received social services.
Conclusions: Maternal demographics and health care utilization predict infant immunization rates. Use of these variables may permit early identification and case management of mothers of infants at high risk for immunization delay.