The purpose of this metasynthesis is to describe and interpret qualitative research relating to midwife-led care to see if it sheds light on why low-risk women experience fewer birth interventions within this model of care. Eleven articles were included in the review. Three themes emerged: (a) relationally mediated benefits for women that resulted in increased agency and empathic care; (b) the problematic interface of midwife-led units with host maternity units, stemming from a clash of models and culture; and (c) greater agency for midwives within midwife-led models of care though bounded by the relationship with the host maternity unit. This metasynthesis suggests that lower rates of interventions could be linked to the greater agency experienced by women and midwives within midwife-led models, and that these effects are mediated, in part, by the smallness of scale in these settings.