Most obstetricians and pediatricians would agree that the examination of the pla centa often helps to explain an abnormal neonatal outcome. As early as in 1892, Bal lantyne wrote that A diseased faetus without its placenta is an imperfect specimen, and a description of a foetal malady, unless accompanied by a notice of the placental condition, is incomplete. Deductions drawn from such a case cannot be considered as conclusive, for in the missing placenta or cord may have existed the cause of the disease and death. During intrauterine life the foetus, the membranes, the cord and the placenta form an organic whole, and disease of any part must react upon and affect the others. Similar thoughts were succinctly detailed in Price's discussion of his concept of the "prenatal biases" as they affected twins. His contribution also admonishes us that placental study is a sine qua non for a more perfect understanding of fetal develop ment (1950). Despite all this understanding of the past and appreciation for placen tal disease, great resistance still exists to performing the task of placental examination routinely. For many pathologists, therefore, the placenta has remained a mysterious organ.