Abstract ♦ In our study, we present an examination of the stressful effects of perinatal events and trauma based on international and national literature, with a particular focus on twin pregnancies where the perinatal death of one fetus affects the relationship between the healthy newborn and the mother. We describe the importance of cortisol testing of transgenerational stress responses that may support or refute hypotheses of this complex phenomenon. Moreover, we attempt to use third trimester stress tests to investigate the mother's experience of childbirth, with a particular focus on how this traumatic experience influences early attachment processes and potentially destabilizes them. As a number of research findings show that perinatal trauma has a marked impact on the mother's emotional stability and the development of attachment to the child, we seek to use these findings to justify our objective.