BACKGROUND: The birth of a preterm infant has a long-term impact on both parents. Mothers report more stress and poor adjustment compared with fathers. Influencing factors, such as family situation and health status of the child, can support or weaken the coping ability of the parents. Studies on experiences of fathers are sparse.

AIM: The aim of this research was to study how mothers and fathers of preterm infants describe their experiences of parenthood during the infant's first 18 months of life.

METHODS: Seven consecutively selected sets of parents of preterm infants born at </=34 weeks of gestation with no serious congenital defects were interviewed 1-2 weeks after the infant's birth and at 2, 6 and 18 months of age, and the findings were analysed using a phenomenological method.

FINDINGS: Internalization of parenthood was described as a time-dependent process, with four syntheses of experiences - alienation, responsibility, confidence and familiarity. Within the syntheses, similarities in how mothers and fathers described their parental roles involved concern for the child, insecurity, adjustment and relationship with the child. Regarding differences, mothers experienced having more responsibility and control of the care and a need to be confirmed as a mother, while fathers described confidence in leaving the care to the staff and wanted to find a balance between work and family life. Important turning points in parenthood experiences often occurred when the infant could be removed from the incubator, discharged from the ward, and when the infant looked normal compared to full-term infants.

CONCLUSIONS: The structure of the phenomenon of parenthood was formed by the integration of the syntheses of alienation, responsibility, confidence and familiarity. The structure seems to be based on the parents' expectations of the parental role, the infant's health condition and the health care environment. These interacting factors are influenced by cultural beliefs.