The child whose mother is diagnosed with borderline personality disorder (BPD) is at risk for developing this disorder. The mother with BPD may be limited in her ability to negotiate a secure attachment with her baby. Mothers with BPD may have difficulties with bonding, internalization, affect attunement, and attachment. Because it is through mirroring and mentalization that a child can learn emotional regulation and master the early stages of development, the child may fail to develop object constancy and master the tasks of separation and individuation. The authors present two cases of patients with BPD. The first case is of a patient with BPD who, after surrendering custody of her two children to their father, participated in weekly Dynamic Deconstructive Psychotherapy sessions for two years. The second case is a mother with BPD who presents for dyadic therapy with her three-month-old daughter. In each case the mother developed insight regarding her relationship with her mother and how that relationship affected the relationship with her own child. The author concludes that psychiatry should consider prepartum screening for BPD and if necessary, early dyadic intervention.