Histological analysis of spontaneous abortions with trisomy 2: first description of an embryo.
Three spontaneous abortions with trisomy 2 were analyzed histologically. In one of these, beside chorionic membranes and villi, yolk sac, yolk stalk, body stalk and an embryo are described. Concerning the development stage there seems to be an order; villi and body stalk (16 days), embryo (end of 3rd week to beginning of 4th week) and yolk sac with yolk stalk (2nd half of 4th week).