[How I investigate...fetal pathology.  Technique and value of the fetal and placental examination and the perinatal autopsy]. 
Fetal pathology is a recent field in pathological anatomy, knowing at the present time an important technical and theoretical development.  However, it is still insufficiently used to resolve cases of fetal death in utero, or peripartum or perinatal.  In this paper, we describe the basics and the techniques used during the fetal examination.  We underline the values of these techniques for the understanding of failures of pregnancy and for orientation of the genetical advice for future pregnancies.