The purpose of this study was to determine whether antepartum treatment of chlamydia infection resulted in a change in incidence of maternal infection in the intrapartum and postpartum periods as indicated by the incidence of maternal febrile morbidity or antibiotic therapy. In June of 1986, an inner-city tertiary-care center nurse-midwifery service began including diagnosis and treatment of chlamydia infection in routine antepartum care. In this retrospective chart review, the incidence of intrapartum and postpartum infection among women who delivered in this caseload between May 1985 and May 1986 (the last year prior to the routine chlamydia diagnosis and treatment) was compared with that of women who delivered between July 1986 and July 1987 (the first year after initiation of the testing). No significant differences were found. Implications for the development of research projects within nurse-midwifery clinical services are discussed, along with methodologic problems that may ensue when attempting to study changes in outcome in ones' own service.