[Death in utero of a twin during the 2d and 3d trimester of pregnancy].

The study of a series of 9 cases of monofetal death during the last trimester of a twin pregnancy, permits to emphasize the relative frequency of this accident (7.14% in our series, markedly higher than those noted in the literature). An early diagnosis, essentially on ultrasonography, of monofetal death, enables monitoring of the mother and the surviving fetus for whom there is a non negligible risk. It is often necessary to deliver this fetus as soon as it is mature. Systematic and repeated clinical and ultrasonographic monitoring of any twin pregnancy during the third trimester ensures, in a large number of cases, prophylaxis of this accident.