[Fetal thoracopagus. Echographic diagnosis at 26 weeks].

The authors report on one case of thoracopagus discovered by echography carried out after 26 weeks of amenorrhoea. The pregnancy was terminated therapeutically by hysterotomy when common viscera were identified (heart and liver). Echographic diagnosis during the first part of pregnancy allows evacuation to be carried out by the vaginal approach. The authors summarize the criteria for echographic diagnosis and also the epidemiological and embryological data required for assessing the prognosis.