“…Excluding two cases with iatrogenic factors contributing to the prematurity, the rate still would have been 25 % . Of 22 previously reported pregnancies delivered beyond viability, 11 (50%) were premature [Aberg et al, 1978;Beck et al, 1980;Petres and Redwine, 1981;Redwine and Hays, 1986;Rodeck et al, 1982;Rodeck, 1984;Antsaklis et al, 1984;Kanhai et al, 1986;Dumez and Oury, 1986;Kerenyi and Chitkara, 198 11. There are no known prior reports of successful selective terminations in documented monochorionic pregnancies. These fetuses, which may be discordant for severe anatomical abnormalities, commonly share placental vessels which could lead to the death or possible compromise of the normal fetus after termination of the abnormal fetus [Benirschke, 19611. Much of this concern stems from reports of documented brain damage in the survivor after the spontaneous in utero death of a co-twin [Benirschke, 1961;Reismann and Pothak, 1966;Moore et al, 1969;Koronyi and Kovacs, 1975;Melnick, 19771.…”