[Incidence of abortive ova among spontaneous abortions].

345 spontaneous abortions of the period 1975/76 are investigated histologically. 174 of them content chorionic villi (100 per cent). Among these we have found 91 abortive ovas (52.3 per cent), 7 hydatiform moles (4.0 per cent) and 35 histological regular abortions (20.1 per cent). Furthermore, 41 cases are suspicious of abortive ova (23.6 per cent) and, 22 cases show signs of early disturbances of placental maturation (12.7 per cent). In all groups there is inflammation of the maternal side and of the endometrium. Regressive changes of the villi are particularly severe in abortive ovas and in the suspicious cases. On the base of our own study of legal abortions as well as this material of spontaneous abortions we estimate the frequency of abortive ovas among all the pregnancies for about 15--25 per cent.