Introduction: Monochorial twin pregnancies are characterized by the presence of vascular connections between the twins. These connections can be at the origin of pathologies such as the transfused/transfuser syndrome or the TRAP syndrome which is defined as the association of a headless, acardiac twin with a healthy twin, which is the subject we will study and then review the literature.
The clinical case: The case of an acardiac, headless twin which was not diagnosed during pregnancy and was discovered at birth.
Discussion and conclusion: The TRAP syndrome is a very rare phenomenon. Yet, it is crucial to diagnose it as early as possible during pregnancy so as to offer adequate supervision. It is associated to a high death rate in the healthy twin caused by anemia and heart failure. There are therapeutic means to stop vascular anostomoses between the twins so as to perform a selective feticide.