Theories of professions and healthcare organisation have difficulty in explaining variation in the organisation of maternity services across developed welfare states. Four countries - the United Kingdom, Finland, the Netherlands and Canada - serve as our case examples. While sharing several features, including political and economic systems, publicly-funded universal healthcare and favourable health outcomes, these countries nevertheless have distinct maternity care systems. We use the profession of midwifery, found in all four countries, as a 'touchstone' for exploring the sources of this diversity. Our analysis focuses on three key dimensions: (1) welfare state approaches to legalising midwifery and negotiating the role of the midwife in the division of labour; (2) professional boundaries in the maternity care domain; and (3) consumer mobilisation in support of midwifery and around maternity issues.