OBJECTIVE: to describe how midwives experience the care of women who are at high obstetric risk or who have an obstetric complication during pregnancy, childbirth and early parenthood. DESIGN: a qualitative approach using a phenomenological method. PARTICIPANTS: 10 Swedish midwives, recognised as highly skilled clinicians with at least five years of clinical experience in the studied context, from four different hospitals. FINDINGS: the essence of midwifery when caring for women at high obstetric risk or with a manifested complication was defined as 'a struggle for the natural process'. Women's transition, physically as well as emotionally, during pregnancy, childbirth and early parenthood, was described as a genuinely natural process. The midwives' struggle consisted of encouraging and preserving this process within each woman. It was based on embodied knowledge and included a balancing between the medical and natural perspectives. Prerequisites, and therefore part of the struggle for the natural process, were sensitivity to the spontaneous, mutual interaction with the woman and enduring presence. KEY CONCLUSIONS AND IMPLICATION FOR PRACTICE: the midwives' responsibility is to promote the natural process during pregnancy, childbirth and puerperium within every woman at high obstetric risk or with obstetric complications. The findings could serve as a basis for reflection on the professional role of midwives, and on the organisation of modern maternity care.