ABSTRACT: Women who deliver preterm infants are at a much greater risk for repeating a preterm birth (PTB), compared to women without a history of PTB. However, little is known about the prevalence of the risk factors which account for this markedly increased risk. Moreover, little or nothing is known about the feasibility of providing treatments and services to these women, outside of the context of prenatal care, during the inter-conception period, which provides the best opportunity for successful risk-reduction interventions.The Philadelphia Collaborative Preterm Prevention Project (PCPPP), a large randomized control trial designed to identify and reduce six major risk factors for a repeat preterm birth among women immediately following the delivering of a preterm infant. For the women assigned to the PCPPP treatment group, we calculated the prevalence of the six risk factors in question, the percentages of women who agreed to receive high quality risk-appropriate treatments or services, and the of rates of participation among those who were offered and eligible for these treatments or services.Urogenital tract infections were identified in 57% of the women, while 59% were found to have periodontal disease. More than 39% were active smokers, and 17% were assessed with clinical depression. Low literacy, and housing instability were identified in, 22 and 83% of the study sample, respectively. Among women eligible for intervention, the percentages who accepted and at least minimally participated in treatment ranged from a low of 28% for smoking, to a high of 85% for urogenital tract infection. Most PCPPP enrollees (57%) had three or more major risk factors. Participation rates associated with the PCPPP treatments or services varied markedly, and were quite low in some cases, despite considerable efforts to reduce the barriers to receiving care.The efficacy of individual level risk-reduction efforts designed to prevent preterm/repeat preterm in the pre- or inter-conception period may be limited if participation rates associated with interventions to reduce major risk factors for PTB are low. Achieving adequate participation may require identifying, better understanding, and eliminating barriers to access, beyond those associated with cost, transportation, childcare, and service location or hours of operation.ClinicalTrials.gov ( NCT01117922 ).