The aim of this grounded theory study was to describe and generate a conceptual explanation of the experience of maternal critical illness. Sixteen participants provided the data which was collected over nine months. The primary data collection methods used in this study were unstructured interviews, and participant observation. Data was also obtained from three published autobiographical accounts. Constant comparative analysis of the data eventuated in the identification of four linear stages, from the first symptoms of illness to a subsequent pregnancy, which were conceptual categories. These categories were named 'identifying a problem', 'being overwhelmed', absorbing' and 'getting on'. These conceptual categories were drawn together in the core category, a basic social process 'Living a divergent experience of childbearing'. The experience of childbearing for the women in this study diverged from the sociocultural expectations of childbearing in New Zealand and from their personal expectations. Their divergent experience of childbearing informed their continuing perception of childbearing as an illness which risked maternal life. These findings have implications for midwifery practice, education and research.