A realist review to explore how midwifery continuity of care may influence preterm birth in pregnant women.

Pregnant women living in different contexts in the United Kingdom, Australia, and the United States at low and mixed risk of complications and with low socioeconomic status or social risk factors experienced continuity models in similar ways, and similar underlying mechanisms may have influenced PTB outcomes. Further research is required to understand how continuity models may influence behavioral change, physiological stress levels, ethnic disparities in PTB and care coordination, and navigation of health services.