In women, pregnancy of a product is how normal conception as well corresponds The structure f unction of U uterus so that multiple pregnancy can be considered as an alteration of normal, perhaps as a border between the physiological process and pathological (1.2}. It is difficult to establish the exact incidence of twin pregnancies and many of the statistical (epidemiological) studies of twins, exclude couples whose products died at birth or before. By eliminating thus stillbirths and spontaneous abortions, incidence rates reflect pregnancies that have come to fruition in advanced gestational ages and the simple conception of twins. Also, it has been shown that twin pregnancies have an increased frequency of spontaneous abortion, pregnancy single product (2.3) as another possibility, can only lost one fetus become known as the phenomenon of "vanishing twin" (4 ). In humans there are two ...