The model was developed from data collected in a study conducted on HIV-infected pregnant women and pregnant women at high risk of HIV infection who tested seronegative at the beginning of the study. Enrollment included a questionnaire on basic epidemiological, health, substance abuse, and sexual behavior data; an 8-month pregnancy questionnaire on substance abuse and sexual practices; and several scheduled examinations and blood sample collections during pregnancy and during regular postpartum intervals. The initial phase of program development involved the integration of clinical, research, and psychological elements of the study. Outreach methodology through interagency collaboration was also established and the early intervention team members were selected and trained. The middle phase of the model development was marked by the twin objectives of reducing placement of children in foster care and providing an ongoing clinical setting conducive to family participation. This phase required close collaboration between the child welfare and health service communities. Future trends should include efforts to reach adolescent mothers, women who deliver during incarceration, and homeless pregnant women. 1 table, 1 figure, and 9 references