Numerous studies have investigated the effects of having an unwanted or unplanned pregnancy on parents. Less is known about the long-term effects of unwanted or unplanned pregnancy on the child and his or her personality. Here we examined in one correlational study and three experiments the associations between birth status (being unwanted, unplanned, or neither) and adult attachment. In general, being unwanted, and to a lesser extent unplanned, was associated with attachment insecurity. Priming thoughts about being an unwanted baby resulted in decreased state attachment security and increased state attachment insecurity. These findings suggest that birth status and knowledge about it play a role not only in parents’ but also in children’s lives—affecting their attachment and mental representation into adulthood.