The number of families being created through fertility treatment with donor eggs is increasing yearly. Women who conceive in this way share a gestational but not genetic relationship with their child, yet there is limited understanding of how mothers experience the mother-child relationship during its formative period, infancy. This study explored heterosexual mothers' thoughts and feelings about the mother-infant relationship in families created through egg donation. Qualitative interviews were conducted with a sample of 85 women who had conceived following egg donation treatment at U.K. fertility clinics. Mothers had at least 1 infant (6-18 months) and were living with the child's father. Interview data were analyzed according to the principles of thematic analysis. The results showed that egg donation mothers used a range of strategies across the transition to parenthood that enabled them to establish their identity as the child's mother and facilitated the process of helping them feel that the baby was their own. This process was individual to each woman, with the absent genetic connection varying in significance between mothers. The strategies employed enabled most mothers to adjust successfully to parenthood and manage any ambivalence and uncertainties associated with nongenetic parenthood. Most mothers felt secure and confident in their position as the child's mother by the end of the first year. (PsycInfo Database Record (c) 2020 APA, all rights reserved).